Hi Terry, Catspaw makes a good point. The guitar (or banjo) sounds completely different when capoed, and you just may prefer that slightly different quality. A few things to remember:
ALL Flamenco guitarists use the capo (virtually ALL the time). It's simply traditional to that style.
Classical guitarists don't use an ACTUAL capo, but they play their pieces in "guitar friendly" keys. They're often looking for sustain and open bass notes, so check how often they play in A, G, and (dropped)D. Am, Dm, and Em as well.
Rarely do you ever hear anyone criticizing Flamencoists and Classical guitarists of lacking technique, but rarely do they go out of what would be called the "simple" keys.
Jazz Players work a great deal from scales and hence a capo would take away some of their fingerboard space. Also they try NOT to use open strings. Many get their sustain from the amp rather than the guitar. Often they use fairly heavy arched and carved top instruments that simply won't sustain like a flat-top or a classical, so a capo would not help much anyway in getting that "open string" sound.
Good rock players tend to borrow from a lot of genres, but scales are still a big part of their style, so you rarely see a capo....but it DOES happen. Keith Richards, seems to use one a lot.
Folkies, Acoustic Bluesers, and rhythm country players are often (not always) primarily singers and truth be known, many do NOT progress past a very basic technique on their instrument. It Sure doesn't make their music less valid, but many use a capo to play in keys that they haven't mastered in the conventional way. We're the ones who often get the flack. I doubt Carlos Montoya ever got dumped on for using a "clamp". (although in fact, he probably DID only play in a couple of keys)
Just remember that Doc Watson, Tony Rice, Pierre Bensusan, and Martin Carthy Constantly use capos...so yer in good company!