If you read the criteria, they exclude studios that no longer exist, haven't been around long enough (seems pre-PS1 is required), or have little variation in their output.
Ah, my bad. Was just in too much of a hurry to mention Black Isle.
"The accumulated filth of all their sex and murders will foam up about their waist and all the whores and politicians will look up and shout "Save us!"...
....and I'll look down and whisper "no."