No reason in particular. FreeCiv isn't browser based anyway.
NationStates is fun, cybernations isn't really anything like it, for example, it doesn't give you these silly legislation prompts.
There used to be a Blockland NationStates group, but everyone quit playing and had their accounts deleted. I used to be in it. Of course, my account was deleted too, I can't really be bothered to log into browser based games every day.