Let contributors receive voluntary donations for their work

The original request was much simpler than these complex scenarios. It was a request to have a simple way for users/readers to reward one another. "[I] would like to see Wikipedia provide a donation mechanism that anyone can easily drop money into for contributions/contributors that/who are valued by others."

That sort of system is not going to make anyone a lot of money; it also is not associated with poisoning wells. It sounds more like a Wishlist/Gift link associated with a userpage.