The goal of the spam is to appeal to web crawlers to increase search traffic, it seems, meaning getting links on pages that point to their garbage websites. The title of the post isn't as important as the body in that regard, since the title won't ever be a link, and changing that isn't going to be a big deal for most of the spammers.
I think a point limit that prevents new users from posting links in questions would probably limit the spam to comments / answers, but that could obviously hurt new users a bit and might not even be possible.
Its definitely super annoying and frustrating though, my heart sinks when I log in and see the Q&A gummed up with spam.