I wonder how long that will last until GitHub bans them for (presumably) massive amount of spam. The fact that it's PRs only, not just issues, makes it a bit harder, but I can't imagine it'd be that hard to abuse
Simply having that easily accessible may got a long way.
Oddly enough, just last week I got in a row with someone else with exactly the same idea: https://www.reddit.com/r/programming/comments/7kp73c/anonymo...
GitHub put a lot of work into their anti-spam systems and this basically let's people bypass that completely. If I was them I'd shut it down right now.
Please don't comment about the voting on comments. It never does any good, and it makes boring reading.