It gets pointed out below, but I think that is really important.

> PHP is a slow abomination. The entirety of Drupal and all modules have to be bootstrapped and run on every request. It runs far too many SQL queries and those queries look atrocious (nested selects, tons of joins, etc).

Those statement don't go together. If it is drupal that is doing too many requests, that is not the fault of PHP.

I'm working partly on an PHP open source blog engine and we are getting way better results. Though caching also helps there, as soon as the SQL statements are properly cached performance increases a lot. That will be true for Drupal, but it most likely will be true for any other CMS that has an equvalent workload on every request. And that those caches help actually show that PHP is not at fault.