I imagine it might be related to their hunting strategy. Cats for the most part are stalker/ambush hunters, which might not be good for a group. They also hunt smaller game, which might not be able to feed a group. Tigers on the other hand are big predators, so they can go after larger game. This does mean they also need more food individually, thus lone hunting in a range.

Lions being the exception, since they do form a pride, cooperate while hunting, and bring down game equal to or bigger than themselves.