People just want to try out the game or just play it for free like you said. I believe more people do the latter. It's funny though, the same people who don't give feedback during tests are the same people who complain the most about the game after release. It's like an enchanted circle of stupidity.
Welcome to the world of beta testing. It's always like this during beta tests. Or just for the past few years. When you guys release Generals 2, or whatever it's named now, into beta, you'll see the same.