Allowing closed generics will lead to massive traffic redirections worse than on .xxx circumstances compelling the concerned to take that string's allowable defensive registrations route.   

[Milton L Mueller] How exactly? Alex, are you falling for the old “magic of the top level” argument? So if someone registers .Book, they magically acquire all the wealth and power of everything associated with books.

I am casting a spell on you, Alex. I have named a file on my server “Gakuru” and soon there will be a http://internetgovernance.org/gakuru on the Internet. With this, I will have gained full control over you. Now, watch Alex stop arguing with me and start agreeing!

Magic is wonderful.