* If you wanted to scale it horizontally, it was ready to do that 15+ years ago
* No problem running it completely stateless
* Deploys are completely sane and predictable, it's just a bunch of files, and even when composer came along it didn't really change that too much
* Performant enough as far as the interpreted web languages go
* No problem writing a RESTful backend in it and fronting completely "modern" client facing tech on the top if you want
* Server side rendering since day 1
Like, it came down to people complaining about some function names / param orders as if it were the end of the world. I think a certain subset of people (shall we call them hipsters?) are just keen on finding new ground where they can rewrite the same boring things instead of working hard to improve the ecosystem of something existing.
I moved on from PHP aeons ago because it got this undeserved bad rap, but I still follow it and would welcome the chance to run it again.