The difference between a female Grey Warden and a Broodmother is that a grey warden only drinks the blood while a broodmother is a corrupted being that has eaten darkspawn flesh. The two dwarves in the deep roads were an example but that one broodmother had a severe case to the point it warped her into something else. Maybe the combination of canabalism and dark spawn taint?
But considering that all the darkspawn are asexual and cannot reproduce, someone has to wonder how does a broodmother get pregnant? A broodfather? Some kind of drone darkspawn then?
But to get back on topic, it's not that Alistair fangirls won't like him less if they can't produce his heir, or won't consider adopting or ancient blood magic/whatever, I guess it's just because of all the things that have happened thus far, it seems like a sucker punch to the gut - especially because of the Morrigan ritual.
And sometimes you can understand why someone would do that, sometimes you can't, most people will eventually get over it, but there are very few people that will like it. Even good friends just messing around will get pissed and forgive you but it's still a cheap shot. I dunno, maybe it's for the bette,r incase the child asks to see a sword up close like Oren. >_>;;
And for all you guys out there saying it's better anyway because we can just lounge and have sex all day (and I highly doubt that's what alistair/pc would do or be allowed to do), you do realize your swift kick in the man hood will be coming up as well right? I don't remember if it was Dave or Mary saying they were equal oppertunists in delivering emotional torture but I do remember it was there somewhere. You know what they say about karma....