Blues, not metal or rock, is absolutely full of microtonal wails and chirps and wiggles and vibrato, and fret pressure very much gives way to a whole new way to think about the strings; not something to press down like a button at exactly perpendicular force to delicately or firmly contact the frets, but strings are something to be grabbed, ripped, whipped, twisted behind the frets. Add to that a hard attack can whiplash a string out of tune by another 10 cents, and we are talking about making this thing a voice, not some synthesized keyboard doodad. It's a human soul wailing. That's the blues.