Although not a member of the gaming community, I would hazard a guess that maxs modelling tools have nothing to do with it's sucess. If polygonal modeeling were all that mattered - lightwave or mirai would lead, Max's strength lie in the fact that it can be disembowled with ease. I would also imagine that its close relationship with windows would have a lot to do with it.
Big FX houses do not use max often, as for it to be effective - it requires way to many plugins that end up costing more than houdini!!!!! - It also has poor Ik and animation capabilities compared to soft. Mind you, on the topic of max and plugins - That afterburn thing is the absolute greatest thing I've ever seen - why not on other platforms?