What can we do for our fellow writers to encourage them not to bite into the write-for-exposure apple?
I'm not sure who any legitimate business could attract at the prospect of working for virtually no money, but for the possibility of name recognition instead.
Think of it in these terms: You've decided to open a nice restaurant, but you can't afford to pay the talented chefs that you want. You place an ad saying, "You must love what you do and be versatile in all forms of cooking. We will pay you a few cents an hour - or a penny every time someone walks in the door - and your name will be on the menu. When the business earns money, you'll have the possibility of earning more." Not sure I would want to eat there, never mind cook there.
If you were a chef, would you bite?
Speaking of which, how about this pitch: "I need some dental work done, but can't afford to pay you right now. When the bright smile you've given me lands me a new job / rich lover / starring role in a feature film, we can consider a small fee. But everyone will see your work in my smile, so the exposure will be enormous."
You dig your toe into the dust under your writing desk and mumble, "But I'm just a writer." Stop that immediately.
Some of the wisest advice I've ever received on this topic came from my former sea captain, also an artist, when we were underway to pick up some passengers. I'd been disappointed by a potential client who had offered me less than the cost of materials for a painting I'd done, demanding, "But you love to do this! And how long does it take you, anyway?"
Said Captain Busam, looking out to the horizon with a slight smile, "Oh, I always tell them, 'That's not the point. The point is, how long would it take you to do it?'"
If you are serious about engaging in any business, you must take your associates seriously, too. If you are serious about being a writer, then for heaven's sake, take yourself seriously first of all.