Tumblr has started banning various tags to comply with the IOS store, rendering posts with those tags unviewable. These include very common tags like "girl" or "big" to outright weird decisions like "suicide prevention" and "mental illness".

That's what I'm saying. They probably crunched the numbers and saw all possible viable alternatives. I hear that (for now) this affects only Apple users, so they probably saw that Android + desktop + some Apple users getting mad is better than Android + desktop + no Apple users at all.