Heck, let's say they weren't laid off. They all moved onto greener pastures in the 15 years since the project was done. And the whole app is written in Perl, since that was in fashion at the time.

I'm not saying that this is a good thing; it's categorically holding us back. But it's how it is, and it's totally a people problem. Browser developers don't want to break existing code, and, because of that, organizations don't realize that their code is broken.