Licensing issues suck.
Well, Blender Game Engine, wasn’t really looked opon when it was created. It was like ‘Extra!’ So, yeah you con’t expect much. But it’s so much easier and faster to use. You model something in the 3D view, press P. Done! Other engines, finish model, export it, something is wrong, go back to model, export it again. Done!
Although BGE has really improved from since it came out. States weren’t always there, they added that in pretty recently. You can use python, which allows you do basicly anything in BGE. Chess games, RPG games, RTS, FPS, have you seen Krum? OR BumperDurby? Or Chess?
It’s pretty amazing what you can do and they all run fairly fast.