In Lois' defense, she only married Quagmire in an alternate future after Peter ignored her in the past.
I can see what Seth and company was trying to accomplish with Lois; they obviously didn't want the character to become Marge Simpson bland, where her role was relegated to just saying "I don't think that's such a good idea, honey..." and cleaning up after her husband and kids, but I think that they progressed in the wrong direction. Lois has alternately become looser, sluttier and coldly vindictive, which, while it certainly stands in stark contrast to Marge, has made her less appealing a character. It's just shock for shock's sake alone, which is basically what the show as a whole has become.