Yea, "friends of friends" is a really weird concept when it comes to people you know from the internet. It creates connections between disjoint communities. Those communities are disjoint for good reasons. They don't have anything in common.
> disjoint communities Really? Think about it: when you befriend a new person, was that person usually a complete stranger to you before, or maybe rather a friend of a friend?
For example, I really like survival horror and horror-themed action games. That's what connects me with one particular woman who shares these interests. However, she's also into My Little Pony and other furry stuff. I don't care about those things or people from those circles.
All those communities are very narrow in focus. They only share one particular interest.