well, that's where you are wrong. Scientists/doctors/etc... aren't people who are smart and have a 300 IQ... It is known in psychology and psychatry that most people with a very high IQ are socially underskilled people. Gifted students (with a IQ over 120)usually are the kind that disrupt the classroom and flunk their classes. Why is that? Well, guess someone would tell you 'what's the difference between those two pitches (avery low E and a piercing high E)' and he played it for you 564 times, I guess after a while you would knock the guy off, or just answer whatever, to ENNNNNND the test, Faaaaast!!!
Well, that's what happens with geniuses. They understand things so fast that they get bored in their classes.

And guess what, some artists are just so bored with promoting, marketing, making marketable music that their music doesn't make it to our ears. One of the best example is Allan HOLDSWORTH, the guy sells his guitars so he can make another record, and HE BLOWS EVERYONE AWAY!! Be it technically, compositionnally, etc... Having a talent for music doesn't make you a potential blockbuster, so I know there are people out there I'd get a kick listening to, but I'll never get the chance to... Bummer...