Oh to be sure, such religions exists. For example, most classical forms of Judaism believe that non-Jews aren't obligated in the 613 commandment. But, that still means that not convincing people is letting people remain fundamentally ignorant about extremely basic aspects to the nature of reality. That's not cool.

To their credit, I suppose, the Lubavitcher Chabad people are promoting a Noahide movement for us gentiles, of which I'm sure you've been made aware. This movement has some interesting implications. For instance, I have a book in front of me which suggests that (if I believed) it would be kosher for me as a gentile right now, in 2011, to set up a private altar and make an animal sacrifice to God. Also, I'm supposed to set up courts of law that can administer the death penalty for violation of the seven laws of Noah. Women and slaves can't be witnesses.