I think that the argument that a low-stat character needs more wits to survive
is not a very good one. If the group has high stats, then it merely becomes up to
the GM to ensure that the opposition is balanced to provide an equal challenge to
the party -- and then wits become equally important than in a lower-stat game, and
high-level characters, regardless of stats, are not dime a dozen.

Of course, there is the matter of a low-stat character in a high-stat party,
or vice-versa. That is the main reason I dislike random-roll character generation
so much. Then the GM is faced with the choice of either making an opposition that
the handicapped PC must use cleverness to overcome, but whom his comrade will
simply walk over, or use an opposition that the more capable characters must use
equal cleverness to overcome, but that the handicapped PC is unlikely to survive,
no matter how clever he is.

In short, higher stats or lower stats is simply a matter of game balance, and
nothing more.