I think the issue is that they picked the Virtual Reality Engine that BI uses for the Arma games. It's a hodgepodge of random code that's just been added to since the original Operation Flashpoint. There are no real improvements aside from some better graphics and physx in Arma 3. A lot of the modern engines have way more tech and probably a much better infrastructure than the RV engine, so I'm sure that is part of the problem. Trying to sort through years of code added on code added on an old framework from 2000.