WTFPL is not a good license for the same reason that "public domain" isn't good. It's not actually recognized internationally. Copyright is the basis of viable international licenses and they need you to turn over the copyright to them (or license it to them or whatever their CLA says).

So, if you did that it'd probably be worse than useless because it might hamper the legal adoption of identical or near-identical code if the fix was such that there was essentially only one decent solution.

That probably complicates things from a legal perspective. I could imagine that that patch can no longer be submitted by anyone.