"I refuse to join any club that would have me as a member," Groucho Marx said.
I feel the same way about writing for free: I don't want my words to appear under the auspices of a publisher or business that won't/ can't pay writers. OTOH, we need to be clear about what "free" means. There's free, and there's writing for a perceived, if invisible, benefit, as I pointed out in the 2002 article: "The Writer's Dilemma: Should You Write For Free?"
Many, many publications expect their writers to write for free --- academic and hobbyist publications, for example. Only YOU know whether the invisible benefits (like a byline) amount to payment for you.
There's a brouhaha over at MediaBistro, because the site doesn't pay for essays.
My take on it? Just write, already. Sooner or later you'll find your way through the swamps and alligators and will make some money from writing. Write.
Here's another Groucho quote: "I wish to be cremated. One tenth of my ashes shall be given to my agent, as written in our contract."