In Reddit's case, that's the deal. You get a website to share things on with other people, and the value exchange involves you giving full licence to Reddit and giving relicense rights to Reddit.
Personally, I find that a very fair deal and clearly other people do as well. I think it actually yields positive externalities because we get things that wouldn't exist otherwise because the transaction costs outweigh the value, but the transaction costs are an inherent cost and I don't want to levy them. Fortunately, Reddit gives me the ability to not levy them and to guarantee that I won't levy them.
In fact, this is part of the magic of Free Software: true freedom to use. Yes, Google can use so much work which was done and it doesn't have to pay any of it back to Torvalds or Greg Kroah-Hartman or even me for the minor changes I made to libraries. This is freedom. I prefer it. And fortunately the world is aligned in this direction.