The use of a capo by a classic guitarist isn't frowned upon if it's done by a competent guitarist in an effort to achieve a particular effect. Flamenco guitarists use a capo (çejilla) all the time.
I have seen a plastic gizmo that can be clamped to the neck of a guitar. It looks like a box and covers the first four frets. There's a wheel or dial on the side. You turn the dial to the chord you want, then strum, turn the dial, strum, and so on. Instant Segovia? Whaddayouthink!??
Mrs. Dora Broberg, a little old lady who ran the Broberg House of Music in Seattle many years ago had been a guitarist of some skill when she was younger. The store kept at least one of each model Martin guitar in stock at all times. She advocated learning some classic guitar technique no matter what kind of music you wanted to play. She sometimes asked a potential customer, "Do you want to play a guitar? Or do you want to play a drum?" Her feeling was that just playing chords on a guitar was only one step above banging a drum.
Why can't you rig up a device to put on a concert grand piano that will allow you to play Chopin at the touch of a button? Well, there is such. It's called a piano roll. But why bother with a piano? Just put a CD on your player.