It's perfectly valid to be dismissive of PHP and you should recognize that. Main reason: there's a metric ton of PHP 5.X websites out there who are never going to be upgraded. That alone is a reason enough to distrust PHP.
If the community makes a concerted effort to introduce automated upgrades of legacy PHP codebases to the newer (supposedly better) versions then I personally would become a fan.
Everybody can tout the newest and greatest. Working with -- and improving -- the legacy stuff is what earns the respect of many, myself included.
(Disclaimer: not a JS dev. You seem to imply some kind of irony that JS devs mock PHP but this is not the case with me at least.)