Why would it matter? Because I like to understand why people work the way they do. Because one of the reasons I come here is to better figure out what lines of reasoning make people behave differently than I naturally might. Because I don't want to misunderstand people's intentions. I've never been much of a "What is, is" kind of a person.
I've always wondered why some people didn't have them. To me, a forum is where you talk to people, leave input, get input, have some back and forths, etc. And to shut that avenue off I've always thought bizarre, and ultimately discourages me from talking to them. But maybe that's what they want!
There's not any pre-judgement. If I find myself wondering the same thing more than a couple of times, I just decide to ask. If I still don't understand, I just ask clarifying questions until I do. In your case, you've gotten sick of dealing with certain people on your wall and you also value your privacy. Question answered. Other people had different reasons than you. What's wrong with that?