Originally Posted by
Wildling
To be fair Sentry's psychic power was at times the given reason why all of Marvel Earth (including Professor X, who was featured in the first couple Sentry stories) didn't remember the guy existed, to the point of being blind to the Sentry tower that was there all along towering above Manhattan.
That he also happened to be mentally frail was just something integral to the character, and also a convenient way (as long as writers bothered with a good explanation, instead of Wasp summoning a random alien worm) for writers to find a way out of directly fighting someone so powerful, like when Sentry invaded the X-Men.