Maybe because the "overcomplications" actually allow for some interesting power constructs that can't otherwise be easily duplicated.
With an Entangle based on INT (for example, a logical conundrum the character is compelled to solve before he can take any physical action), other characters could help "guide" the victim to a solution (ie making INT based "attacks" on the Entangle). With a PRE based Entangle (say, paralyzing fear), a commanding ally could "snap him out of it" with a PRE attack against the Entangle. These are interesting dynamics that would be hard to represent with Mind Control.
An idea that I find most intriguing is an Entangle that is affected by two or more characteristics. Perhaps an entangling rope attack could be escaped with STR or DEX. Or, if the Puzzlemaster traps you in one of his Giant Rubiks Cubes, you *could* simply bust out with STR, or you could solve the puzzle with INT and thereby force it to release you.
Yeah, I think there's a lot of interesting possibilities there. I wouldn't be so quick to dismiss the idea of Entangles against alternate CHA out of hand.