...in general, all the technology progress has been essentially reducing the ability of a mod team to do something significant and competitive. We've certainly seen this over the last 10 years, where, in the early days of somebody messing with DOOM or QUAKE, you could take essentially a pure concept idea, put it in, and see how the game play evolved there. But doing a mod now, if you're making new models, new animation, you essentially need to be a game studio doing something for free to do something that's going to be the significant equivalent. And almost nobody even considers doing a total conversion anymore. Anything like this that allows more media effort to be spent, probably does not help the mods.
Another argument that new tech is mainly aimed towards big teams. It's seeming more that it's procedural content generation that's way behind the times now, not the rendering engine itself.