While I'm not a fan of Blizzard's direction over the last several years, you can't deny that their games still have a level of polish that's far and away beyond most other developers.
Polishing a game to be an objectively good piece of software is a virtue, expecially in light of recent, bug ridden releases. (They are still lacking in the tech department though, lots of missing 64bit executables and proper multicore support here and there..).
But that alone does not an excellent game all around make, sadly. You know, the stuff they used to create. They just produce ok-to-good games nowadays, a lot better than most allright, but a far cry from the glorious past.
They hold themselves to a high standards, fans hold them to high standards, everyone does, let's say it. Always stating "They are still better than most!!!", while true, just rings as a lame excuse, a cheap cop out, nothing more.
Just like the amazing, brilliant student with straight As, who one just "decided" to grow lazy, aim for Bs at best, while still calling himself better than anyone else and boasting endlessly with the ladies to impress them. True statement, but..daaamn.