I tend to agree with Willie-O, that it's really a question of good musicianship, not the instruments that are used. As he correctly points out, there are any number of electric guitarists that play with great nuance and subtlety. Unfortunately, so much of the music that we hear in public is played in bars, where there is a lot of noise and little opportunity for the more subtle nuances to come through. It's like trying to carry on a conversation in the middle of a football game; you basically have to shout to be heard, and forget conveying your underlying sentiments with subtle vocal inflections.

I do think that amplification -- of vocals, acoustic instruments, and electric instruments -- can open up some opportunities for more nuanced playing to be heard, in ways that would not be possible without amplification. For instance, if I am playing lead guitar breaks unamplified with a bluegrass band, I have to play as loud as I can just to be heard over the other instruments; even though I'm playing an acoustic guitar that has great potential for subtlety when played solo, that potential is masked by the competition from other instruments. Some subtle amplification can allow the more sensitive side of my playing to shine through.

In a way, preferences for unamplified vs. amplified music are like preferences for stage dramas vs. film. On stage, one has to project, vocally as well as with gestures and facial expressions, in order to be appreciated by those in the back row. When film first came in, stage actors who were trying out the new medium tended to over-act, because they weren't accustomed to the way their stage-based styles would seem excessively emotive on film. Conversely, film actors who try acting on stage need to learn how to project to the back rows, because their subtle expressions just don't carry on stage like they do on film. But both the stage and film have their place, and great art can be created on both. I think the same can be said of amplified music (whether played on instruments originally designed to be amplified, or not) and unamplified music.