I don't think playing fast necessarily 'bypasses' (for lack of a better term)
feel or taste.. it certainly can if it's just 3 note per string scale runs repeating shapes one after another but to suggest that using it to hide the fact a player lacks feel or taste is ridiculous.
I think the main issue with playing fast, in alot of cases is that players look more at the speed than the note choice and thus forget/care less for the road in which they are taking the melody and thus the very thought of 'playing fast' springs up a scenario in our heads of a guitar player picking 16th notes at a metronome beat of 180bpm in a chromatic scale.
As for using high tempo to 'hide behind technique and flashy speed', while this is not always the case... I've seen this get abused many a time and I do understand/feel your pain
That being said I do encourage guitar players to work on their speed both high and low tempo because plainly put, you never know when you're going to need to use them. Think of your guitar technique and abilities as a tool-belt: I'd rather have high tempo, arpeggio, sweep picking on there just in-case I need them rather than not having them there all because I want to work more on slower stuff and 'playing with feel'.
Bottom line is this: If you're serious about developing your skills on your chosen instrument, you should be prepared to study all aspects and it's ranges instead of just the stuff that you wish to incorporate in your music at that given time. It's the added flavor and feel of -enter guitarist's name here-
that makes the music, musician & improvisation so inspiring to the listener and is what makes every musician different.