It's really quite simple. Beer is an acquired taste. This is another way of saying it tastes really bad to those who haven't been drinking it for a while. It also means that even styles adjascent to the ones you're used to might taste bad at first. (Hello, gueuze!) The only reason you wouldn't say "eww, this sucks!" when you first try something unfamiliar is because you know that beer is strange and takes time to get used to.
I remember feeling this way about practically every new style I tried when I was starting out! The only thing keeping me drinking was the idea that someone, somewhere thought this stuff was good. Sounds stupid, but taste is basically a social construct anyway. You just have to get it through your thick skill that this particular form of decay and decomposition is OK to eat, while this one is not.
You can't expect an ordinary beer drinker — or even your average beer geek, for that matter! — to tell the difference between an infected beer and a stylistic choice. Beer fanatics know what an infected beer tastes like. Most people don't. Most people think your average shelf sour is just as strange as a beer that has been unintentionally infected.
Hence, no one complains except the crazy people on beer forums. (And even there, it's often for political reasons — greed and poor craftsmanship — and not necessarily actual taste. Many infected beers get reviewed well.)