Here's the thing about Tumblr
You scroll through the feed, thousands of miles away from hundreds of people you will never meet, and see people you might become friends with – but they are swamped with hundreds of responses to anything they post.
It's kind of like arriving at a party where you only vaguely know a few people, and they are surrounded by a wall of mayhem that you really don't want to have to either compete with, or deal with.
So you just quietly stand there on your own, nodding at acquaintances as they pass by, and watch the world go by without really being a part of it.