didnt the beatles do a similar thing? before lsd, they were a boy band. their true expressions came out post-acid. the difference between the beatles and the dead, is that the beatles went more mainstream with it, and the dead didnt. the dead didnt care about money, and sales and all that. they were strictly about the music.
and they were that good. jerry garcia is in the top 10 rock guitarists ever, and every other member of the group had tremendous abilities. their talent would have remained, the acid merely steered their talent in a different direction, producing a different type of music