I recently asked myself this question: Am I a yarn snob? The honest truth is.....I don't know. Being a spinner, I naturally prefer fibers like wool, silk, cotton, alpaca, camel down, etc. Once you feel the real stuff you don't want to work with acrylic if you can help it.
However, not everyone I knit for would want to care for something like 100% non-superwash wool or silk, especially if it is something that is going to be laundered quite often. I am finishing up a baby blanket out of microfiber that is super soft and will be easy to launder. Our daughter has 5 children and is expecting her 6th in a month and the one thing she doesn't have time or room for is laying something out to block and dry. Maybe, when they relocate to Texas in a few years that will change. I can always wash and block stuff myself!