Your criticism seems to be well-founded in past experience, however as a casual developer and supported of Drupal sites for my own businesses and some charities, it 'just works', looks good, and is reasonably easy to look after. All my clients, are happy with the results. I have not ever bothered to examine performance nor work on it beyond enabling caching because there hasn't been a need to.
Now admittedly these are not sites with millions of visitors, however several run on a single 2GB RAM VPS. And, yes, there is the problem with version upgrades, which in the past I've handled by a site redesign every several years, and paying someone to handle the data migration / mapping.
From my point of view Drupal 'just works' for me (and several other web guys I know), clients are happy, hosting is cheap, and site performance is fine. In a world where there is always something to do, I still don't intend to look into it further than this, or fret over changing CMS because there is no need to.
I'm happy it works for you. Personally, drupal would need to do some very serious non-sexy re-factoring before I would consider it for any future project.
Now admittedly these are not sites with millions of visitors, however several run on a single 2GB RAM VPS. And, yes, there is the problem with version upgrades, which in the past I've handled by a site redesign every several years, and paying someone to handle the data migration / mapping.
From my point of view Drupal 'just works' for me (and several other web guys I know), clients are happy, hosting is cheap, and site performance is fine. In a world where there is always something to do, I still don't intend to look into it further than this, or fret over changing CMS because there is no need to.