At $1500/yearly subscription, 30,000 licenses is $45 million a year. Don't foreget about everyone who works at Autodesk that isn't a developer but stil involved with the product. And then there are plugin writers (are there commercial plugins for Blender?) and resellers etc
There was some unrest in the community just recently when Ton reminded everybody that Blender is GPL and that commercial plug-ins need to be GPL as well.