Looks like Guido added the original code about 25 years ago. Since he removed himself from the other thread during that discussion, I'm going to assume he's not interested in thinking about it any more.

As the original comment says, it's a hack, but I guess there may have been an OS around at the time that would deliver signals across processes? Maybe after fork? It might be worth pinging python-dev briefly just to check if anyone there knows of an OS that might do this.

That said, the comment change in the PR looks totally fine to me. I'm just hesitant to remove something that's apparently been working for a quarter of a century ;)