Seems like in my area there is a pretty steep decline of available women over the age of around 25 or 26, and then by the time women are 30 they're either damaged goods/full of baggage or are seeking marriage or both.
Pretty much everyone is full of baggage and/or damaged goods at 30. It's called life happens. In fact, I am loathe to trust someone that can't admit to undergoing some sh!t by the time they are 30. If you take any risks in life, you will get burned at some point.
And yes, random hookups can get harder the older you get, because the available pool is reduced and you are perceived differently.