Right you are! But think about it - we have personal space in our minds as well. It's where beliefs are stored. Now we don't want them to get hurt, so we protect them. This is not that different from physical personal space.
I get that "space spaces" and "personal space" both have the word "space" in it. But if we're discussing scientific studies, it's not constructive to compare the two. Unless you have something really substantial (and accurate) that adds to the conversation, I think it's time better spent to discuss the article at hand.
I personally think it's a fascinating insight into how humans interpret physical space and the implications in social situations.