Er, Vri, you did defend that article. You posted it as a way of showing that it was "not exactly anti-single parents" when it pretty clearly was, right there in the article.
I don't know if the 70% statistic is true or not, but it's meaningless either way, because it doesn't attribute cause and effect, just assumes it. If it is true, is the crime/addiction link there because people discriminate against single-parent families, or because one person is doing two jobs, or because single-parent families are more likely to be in poverty, or what? Bashing single parents - and claiming that they aren't families is so much easier (and nastier) than actually addressing and seeking to solve any problems that do exist. And it's not like single parent families will cease to exist if you shame them and hate on them hard enough - bereavement happens, domestic violence happens, irreversible breakdown of a marriage happens, spouses men behave badly and then abandon their families. Some people do plan to be single parents, but many more find themselves so unwillingly and unexpectedly.
And on the equal marriage thing - if you deny a gay person something you are happy to allow a straight person to do, then that's pretty much the definition of discrimination.