Yes, there is a freeloader problem - the vast majority of corporations using Linux get real business value but give back zero. But if you scare away the majority of businesses with your license, you haven't solved that freeloader problem.

Easy. If they don't use it, they're probably not interested. If they use it without giving back (or forward), they're probably free loading.

How is that a problem? I take a book out of the library. (That institution is both about free as in speech and free as in beer.) If I become a huge fan, then I might buy the book for myself and start dressing up like the characters at conventions. If I'm not that into it, I return the book.

If one puts something out there for "free" then one is not entitled to a return. It's the model which is broken, not the users!

I was answering the second question, not whether free loading is an actual problem. The answer to that is of course up to the original author, who is entitled to use any license they like.

Regarding your "peek and return" scenario, GPL actually lets you do that, and I wouldn't consider you an actual "user".