I have a stash since I live in the country. If I want to start or finish a project at 10:30 p.m. I can. Because I have a stash. I cant run to the LQS at the cost of gas, so that is my reason to build a stash. Not to mention that I can.
I buy when I get great prices for the most part. Even outdated fabric looks good in a scrappy, darn it, now I want to go buy more fabric!