The reason i fidagree with this is simple... all those skills are typically opposed or frankly have fairly low DCs. At 10th level a sor with a 20 cha and a 14 int (i often see sorcerers with this cheap point buy level of int) can afford to easily have +11 (12 skill ranks each and 5 from CHA) with two of bluff, gather info and diplomacy making the default take 10 result a 20. In opposed rolls they have a +11.
This means that against anyone with corss-class in these same skills or their opposites, and who doesn't have CHA as a prime stat, the sor is VERy likely to succeed. How many fighter do you know who at 10th level have a sense motive that can compete with +11 bluff checks?
The key is, the people he has to be smart enough to avoid, are those for whom CHA is a prime stat and the skills are class skills.
in short, like any other guy trying to get by on guile, he chooses his marks.
I find many players, and some Gms, seem to scoff at cross-class skills as bad investments. The truth is, if everyone else thinks that way, its not true! their own 'efficiency" leaves them vulnerable to cross-class uses, even at 2-1.
this may be the first case of a self-denying prophesy!
FWIW, in my current campaign, a fighter did indeed max his cross-class sense motive and take a 14 wis... he is the best in the party at seeing thru bluffs and the like.
kigmatzomat said:
In other words, you cannot run a pure-class sorceror that "gets by on wits and charm" (as I think the PHB puts it) at higher levels when their high charisma doesn't outweigh their low (cross class) skill rating.