The problem George Broussard has with the issue is that companies like 3D Realms (while they were actually still a game development studio, and now during it's quasi-half-existence as a publisher) cling desperately to old properties as their their only source of revenue. They've failed miserably at actually releasing any updates to their own works or creating new properties, and so their revenue streams has devolved to porting Duke Nukem 3D to the Xbox, PlayStation, Steam and any other platform that comes to mind, and licensing everything else out to separate studios (such as the Duke Nukem Forever, and last year's Shadow Warrior update).
The later, I assume, is the only thing that is holding them together as a corporate entity, along with anything that might of come out of the settlement with Gearbox (if they got anything).
Take away their copyright to those IPs, and companies like 3D Realms would not last another year.
As a result, his reaction to these kinds of comments is totally unsurprising.