I think there are a number of folks, such as myself, who want to see the game made more concise and cohesive.
On the other hand, I belive there are a number of folks, such as myself, that actually enjoy the vastness of this game and wouldn't want to, let's say, lessen the scope. I don't think a cohesion is needed or welcomed. For me personally, the sheer volume of cards is a big part of the appeal.
That someone will have to take the time to errata the cards in a database or whatever card templating program they use?
How about the actual physical cards? What you are talking about would result in literally hundreds of cards being altered...
The biggest benefit of the split clans getting merged would be that it opens up deck-building options and powers up under-powered clans.
While that may be the case (and I guess you are alluding to !Gangrel - imho the only antitribu clan that could use a power-up), it would at the same time give a vast boost to all the other clans (like Tremere, Toreador or Ventrue) that truly don't need or deserve a boost.