Mixed feelings on this. Tell culture allows people to express their feelings directly without prompting, but can also be used manipulatively when insisted on as a behavioral standard by someone who's overbearing relative to the people they're around.

For further reading, here's the blog post that named the concept: https://www.lesswrong.com/posts/rEBXN3x6kXgD4pLxs/tell-cultu...

And further discussion within the same community: https://thingofthings.wordpress.com/2015/05/08/against-tell-...

There were a bunch of tumblr posts on this as well which are more work than it's worth to go recover.