I think your alarm is unnecessary. Remember how Bill Gates underestimated the internet? Accurately predicting the developoments that will come in the computer related industries is tricky business. No one can tell what people will go for when things change. Turbosquid is a showcase for commercial models so it is only natural that they would market to the gaming sector as well. Renderosity is a site for creative exchange, whether or not the operators see fit to include a GMAX section. I think, for now, we're safe.