I'd rather prefer KPA to remain simple and maybe just emit expressive MIDI via MIDI OUT / USB.
This is something I can totally understand although I'm afraid it will require pretty specific features on the guitar/bass like polyphonic pickups and a corresponding multicore cable (from 4 string bass to 7+ string guitars). And then there's still the issue with latency introduced by the software that has to track and convert stuff into MIDI.
Everything else you wrote I agree as well .... and how long would it take for people to ask for more than "just" regular sound synthesis from a couple of basic oscillators but also sampled instruments, wavetable synthesis, physical modelling and so on. I think this is a dark hole of enormous size and the wishes differ so much that we rather use a "synth" of our choice.
In an ideal world there would be a guitar pickup system that does all the work and spits out perfect MIDI without any noticable latency and you just hook it up to whatever sound generator(s) you want. But some synth inside a Profiler? Thanks but no