Magic ears like Zappa's don't come around that often. Add to that the ability to command and drill a band, manage his own production company, be an exceptional studio engineer, have the drive and motivation to be truly prolific in his output and be able to improvise on the guitar in a very unique way...and probably 'lots of other stuff as well'...it's not really that surprising that there really hasn't been another like him in the entire 20th Century.
I can channel my inner Zappa when improvising, but as for all the other 1000's of attributes I'd need - not a chance :=)