Common people can't afford the required infrastructure to host a gTLD, getting requests from all over the world. Especially if it gets popular, it'll be pretty expensive to get into.
True, but that's a reason not to be so free with them in the first place. I see a lot of wannabe-monopolists in this list, eg getting a .actor domain is easily going to be a must-have for anyone who works in film/TV/theater so issuing a TLD for that is basically granting a license to tax that entire profession.
I originally thought this was a good idea when I thought these new TLDs were going to be trickled out in an orderly fashion. As it is, it looks very much like a land grab that only rich participants can take part in. I predict the resulting balkanization of the namespace is going to lead to a collapse of the web within a decade, in the same way that Archie and Veronica eventually fell victim to their own complexity and were replaced by something more accessible.
getting a .actor domain is easily going to be a must-have for anyone who works in film/TV/theater
I'm sure the applicants think the same, but I'm completely unconvinced of that. People have trouble using .info and such already. My guess is that most such TLDs will be dead on arrival; most people don't even type domains nowadays, they search and use links.
Having a good Facebook path is probably more important for most people than any domain will ever be.