A question for unmarried heteroual couples...?

After reading this article: a href="http://nevadaappeal.com/article/20070621/NEWS/106210080" rel="nofollow"http://nevadaappeal.com/article/20070621…/a I have to ask, what possible reason could a heteroual couple choose not to get married, which would also give them the right to complain about not getting the benefits? Doesn't that "ruin the sanctity of marriage" just as much as "gay marraige"?