That some will use the same username which can then be found on OnlyFans is fine. What is not fine is the way it works on FetLife. Women make a low quality post how incredibly horny they are, it gets upvoted and the whole ploy is to redirect you to their business. Primarily rules need to be focused to disable that.
It was a limited scale action to show the impact possible. If reddit indeed won’t move it could become indefinitely. /r/ffxiv already wanted to move it to a week or indefinitely.