Limiting cards is a really good idea otherwise you can get real nasty (and impossible to stop) malkavian bleed decks (bleed, stealth, slealth, bleed, stealth, slealth, bleed, stealth, slealth, bleed, stealth, slealth).
You think 4 card is a problem for the Malkavians? Well, let's see what that actually does to the Malks:
4 Guns, 11 Masters
80 Cards total.
Now, assuming each Veil gets used for 1 bleed and the Pulse gets used twice, he can get 58 points of bleed at a total of +36 Stealth, with 4 Seductions for that extra boost and 4 Deflections for some delightful little surprises. Such a hardship. (Of course, if he hasn't got $$$, he probably doesn't have 4 PV and 4 KD, but hey, why should we let people without $$$ have a shot at the big leagues by allowing them to use extras of the roughly equivalent Lost in Crowds plus Govern the Unaligned?) Mr. Malk can still easily clear the table, but at least you have the consolation of knowing that due to card limits, his deck has become completely, utterly predictable, with no options left for variety within the context of stealthy bleeds.
Now let's look at what 4-card limits do to DEFENSES against our friendly neighborhood Malk. There are 3 main defenses against stealthy bleed: intercept, rush, and bounce. Now the interceptors don't really care about card limits any more than the Malks do, as there are umpty-umph + intercept cards. Tremere and combat Malkavians do just fine. Toreador theoretically could, except with all that intercept about they can't get out any guns and they no longer have any good way to hurt people.
Now the bouncers (people using Deflection/ Telepathic Misdirection to bounce bleeds to their prey) used to cackle madly at the prospect of a Malkavian predator, who they just used to oust their prey. Hearing that Mr. Malk was building an "unbeatable" deck by cranking up the proportion of Conditionings merely increased the volume on their cackle. Nothing like your predator spending extra blood to bleed YOUR prey.
Once again, the Malks and the Tremere are sitting pretty. Granted, with only 4 of each they no longer completely hose the Sneak and Bleed decks, but they have intercept too, so they're still smiling.
Mr. Ventrue, however, can only bounce 4 bleeds (no telepathics for HIM). His cackle dies in his throat. Quick, can he find another defense? Intercept - sorry, no intercept in his disciplines. Rush - sorry again, Fortitude is pretty lousy at doing damage. He's now helpless. Congratulation, card limits have claimed their first victim, as Ventrue degenerates from an outstanding anti-Malk deck to a very low speed bump.
Toreador bleed bouncers get hosed too. Their remaining bounce card (Telepathic Misdirection) isn't even as good as Deflection, and the poor man's bleed bounce (Telepathic Counter) doesn't do much good when you can only have 4. They, too, have become speed bumps. At least they are high speed bumps as the combination of Auspicious intercept and Celeritous Dodges allows them to survive a long time.
What about rushers? Rush is based on the principle that the best defense is a good offense. In rush, you play a combat god deck, with lots of cards for entering combat (Bum's Rush, Haven Uncovered, etc.) Typically a nasty Brujah rush doesn't care how many Bleed or Stealth cards a Malk predator has because he sends the Malks to torpor as fast as they get influenced out.
Under 4-card, though, things change. With only 4 Bum's Rush and 4 Haven, Mr. Brujah can only get into combat 8 times (and the Havens can be Suddened). At most, he can get 2 players. Typically, he can't even get one, because with only 8 enter combat cards he's guaranteed a dry spell where he can't find an enter combat card and he's just going to get mowed down. It will only take one surviving Malk to do the job. Victim #3.
Nosferatu and Gangrel lose rush for similar reasons. They have access to raven spies, at least, so if they are very lucky they will a) not start with a Malk predator, b) draw and play multiple Ravens and Sports Bikes, c) not get their one +2 interceptor socked with a Seduction and d) manage to have the right cards in hand to torporize multiple Malkavians. Not as long a shot as winning the lottery, but, still, 9 times out of 10, thump thump- more speed bumps.
So what do we have? Malkavian stealthy bleed decks are reduced from being able to clear the table to - being able to clear the table slightly more slowly. Sniff. Meanwhile, 5 out of the 7 clans lose the (otherwise very effective) defenses against Malkavian stealth and bleed. Jeez, what more would they want?
Jyhad is not Magic. In Magic you have multiple cards to permit functioning under card limits. In Jyhad, you have multiple + intercept and + stealth cards because you can only use one of each and they would like it to be possible to get intercept or stealth above 1. Under card limits, this has the decidedly peculiar side effect of permitting intercept and stealth decks while the other fascinating uses of those disciplines get hosed.
Magic was originally designed with the assumption that people would play in "universes" of less than 2000 cards. After all, what kind of nut case would spend hundreds of dollars to win a card game? Hence Magic was designed with the assumption that players would face loose card limits - not exactly 4, but unlimited numbers just wouldn't be available. When it became clear that some people would pay thousands to win, and have access to more or less unlimited numbers of any card, they slapped on a 4-card limit in a desperate attempt to simulate the limits they had expected. It took a lot of the flavor out, but they had to do something. It really didn't fix things, even - look at the length of the restricted list! Since about Arabian Nights, WotC has been trying to eliminate the need for card limits so the game can be played as intended. They haven't succeeded, but at least they are trying.
By the time of the design of Jyhad, WotC knew that people were going to have lots of the cards. Jyhad was designed on the principle that people were going to have access to unlimited commons, and perhaps to unlimited uncommon and rares too. For Jyhad to work, you must have unlimited numbers of many essential cards - Bum's Rush, Deflections, Dodge, Undead Strength, Flash, Fake Out, Telepathic Counter, etc. Otherwise the defense/offense, vote/combat/bleed, and clan balances go poof. Yes, there are some problem cards, like Wake, 5th Tradition, and Majesty (which actually is one of the cards you need in quantity), but those have to be addressed on an individual basis. You don't fix a few problem cards by wrecking the whole game structire.
The great tragedy of WotC's earlier mistake with Magic is this 4-card business. It would be excessive to punish WotC for that one mistake, especially given that they recognized it promptly and are trying to fix it. But that mistake is being used to punish the entire CCG industry. Every game that comes out, people want to put 4-card limits on - whether the limits are inadequate (Rage), irrelevant (INWO), or downright destructive (Jyhad). Almost every game is getting stuck with all the pains of card limits - differing effects on different cards, the tedium of card counting to ensure legality, the mindlessness of throwing in 4 of each necessary card, etc. After playing a good no-limits-needed game, believe me, card limits will drive you nuts.
In CCGs, as in underwear, one size does NOT fit all.