They seem pretty stupid to me, actually. At least in most animes. It's not like I would ever want to actually get a yandere gf anyway, it's just a fantasy setting- They're great tools, but what would I use them for anyway? Make me food? No, thank you. It's not like I'll ever need a yandere for anything.
In that prospect, I may not be into anything. I don't feel any need for romance with anything, and even when thinking of my favorite heroines, like Akane, my thougts go directly to their objectices and goals. My favorite heroines would be great friends, but I can't imagine myself entering a romantic relationship with anyone if not for some sort of goal- money, influence, etc.