"I do think that one of the big problems for PHP is that people who voluntarily do PHP instead of something else are immediately suspect"
I write lots of PHP for work and for most of my personal projects. Learning other languages is just syntax, when you know the core concepts.
I once converted a personal project over to Python 3.X in a couple of weeks and it was much slower and took more memory than the PHP counterpart, so I scrapped it.
"However, most PHP I run into is not modern"
This may be the case for you, but I've worked with lots of companies that built their apps using PHP and most are modern.
"but I can't really imagine doing it myself just because of all the flashbacks to code that parses query parameters and calls the database in the middle of a templated for loop"
I'm sure there were many poor practices with other languages 20+ years ago.
I think many here on HN are living in a bubble where most companies use cool new frameworks and are looked down upon for their stack choices.
I haven't been out of work in the past two decades, and I work almost exclusively with PHP code bases. I suppose I should be happy for all of this language snobbery, because I make a very good living and haven't spent more than a few days between gigs.