Clients generally don't care about or understand your technology choices. People and process management are at least as important to freelance success as programming or design skill. That much I definitely agree with.

I wouldn't describe my clients as hell, though--not by a long shot. But I've been freelancing full time for seven years, moonlighting five before that, and I've learned to avoid (and am able to do without) bad clients for the most part.

Way back in the beginning, when I didn't much know what I was doing and sold even that work way too cheap, there were some pretty bad times.