why is Tumblr so broken?

In its mobile app (so no xkit) Tumblr keeps showing me stuff I haven't subscribed to, even though I unchecked all the options for it to mess with my dash (the "best first" as well as the option to show what others liked to me). And that wouldn't be that horrible now and then, but it keeps showing me the same things again and again, even after clicking the same thing away as uninteresting half a dozen time.

Just now I resorted to blocking an account just to (hopefully) make Tumblr stop showing it to me again and again, even though the user didn't do anything to me nor was the post upsetting, I just didn't want to see it, especially not more than once. I'm not sure that Tumblr is really doing these blogs a favor by "promoting" them like that.