Some of us take great care in amplifying our acoustic instruments with quality pickups and equalization. The purpose is to be able to mix the sound for a larger audience with clarity and without feedback. Sometimes things that are quiet or have subtle dynamics need to be heard.

Each room has acoustic properties that change due to weather, humidity and even the amount of guests and if they're wearing coats.

People who insist on only natural amplification (which in some situations can be beautiful) may unknowingly encourage only loud strumming.

If someone thinks folk music should never use pick ups (which have gotten quite good these days) or microphones...they're missing out on some nice recorded music.