Mick Taylor was definitely a true virtuoso.I would suspect that the
Stones picked Mick Taylor because:1-He was a relatively obscure
guitarist,so therefore he wouldn't have had a previous "fan base" to
compete with Jagger and Richard,and 2-rock music at the time was
evolving into extended guitar jams made popular by people like
Hendrix,Jeff Beck,and Clapton..and Mick Taylor was more than capable
of playing like that..especially live.Taylor did some great work with
Jack Bruce of Cream in the late 70's..very very intense stuff.Of
course,when rock music moved into disco,punk,and reggae influenced
sounds..the long guitar jams seemed to have been somewhat
dated.Which,as we know,was around the time Taylor left the
Stones.That's always been the beauty of the Stones..to take the
current sounds,incorporate them into their own compositions,and still
make them sound totally original..a lesson they surely had to have
learned from Brian.(I'd say the exception to this would be the
dull "Fool To Cry",or maybe "Emotional Rescue").