It literally happened with more than 50% of the games that I unpublished when the member was still an active user. Frequently, I'd get no PM back, they'd just sneakily republish. I wouldn't say that removing games was rare in the past, maybe only slightly rarer than now.
If a storygame is so bad that it doesn't meet the very weak minimum site standards, then I'm not going to bother unpublishing it and risk having it come back from the dead (remember, it won't go back on the 'new games' list, and we probably won't find it for awhile). If someone writes a storygame that bad, then they aren't losing much time. Tetris claims that it took him two weeks to write that game, but he had only had an account for a few days when the game was published. In reality, the storygame probably took an hour.
I don't think we're discouraging writing, I think that we're encouraging writers to put more effort into their writing.