As someone who used to work over there (Pornhub, Youporn, ...), it is not a question of legacy.
If you use PHP the way it's meant to be used, you are not gonna have any surprise, and it'll run faster than the alternatives (or close too), for lower development time, as well as easiness in finding developers.
Also, the article is a bit off on some points, a website like Pornhub (100Million+ pageviews/day), is on the most standard stack you could imagine: PHP, Apache, MySQL, Memcached/Redis. Varnish get mentioned a lot, but when I was working there (not so long ago), it was not in use, and as far as I know Youporn might be the only one relying on it right now.
If you know what you are doing with PHP, you will have no surprise, no performance issue, and maintenance will be trivial. But sadly I have to admit few PHP developers actually use PHP the way it should be.
If you use PHP the way it's meant to be used, you are not gonna have any surprise, and it'll run faster than the alternatives (or close too), for lower development time, as well as easiness in finding developers.
Also, the article is a bit off on some points, a website like Pornhub (100Million+ pageviews/day), is on the most standard stack you could imagine: PHP, Apache, MySQL, Memcached/Redis. Varnish get mentioned a lot, but when I was working there (not so long ago), it was not in use, and as far as I know Youporn might be the only one relying on it right now.
If you know what you are doing with PHP, you will have no surprise, no performance issue, and maintenance will be trivial. But sadly I have to admit few PHP developers actually use PHP the way it should be.