> It's not like a team wanted to rewrite it in PHP, which we can all at least agree would be madness.

That seems like the same argument that TFA is making, but in reverse. I think it's just as invalid. PHP is a perfectly fine language for many things. There is plenty of greenfield development being done in PHP these days + a substantial amount of PHP in production all over the place. Unilaterally writing it off as "madness" seems pretty disingenuous to me.