Like Facebook, WordPress and MediaWiki? Bashing PHP is a popular pastime, but front-end performance and inclusion are not to be scoffed at. Especially not if your target audience has a different standard of living than that of a major European city.
Personally, I'm much more worried about optimizing heavily third-party dependent front-end code to perform well on old laptops and cheap phones than I am with scaling up and load balancing a server-rendered site.