Like it or not, competition drives the market. No competition, no incentive for companies to improve.
There is plenty of competition for 3D engines, BRL just doesn't seem to be motivated to compete any more.
There were promises around the time BlitzMax was released that BRL was working on the "next gen" version of the Blitz3D engine (Max3D), and that was exciting, because Blitz3D, in it's time, was a very competitive engine (compared to other engines), and I think we all expected a similarly excellent engine.
Well, so far, nothing has come (from BRL), and even a few third-party 3D engines have been written (from scratch) since then and BRL still isn't even sure what direction to begin with Max3D.
You're right, competition drives the market. Unfortunately BRL doesn't even seem to be competing any more, and maybe for good reason. There are so many amazing modern engines out there today (some for free), so maybe they feel like it's useless to compete in the same area. I know it wouldn't stop me (I'm a competitive type), but maybe not for BRL (aka. Mark Sibly - is there anyone else?)