Tumblr staff just haven't accepted that Tumblr users are extremely stubborn, anti-algorithmic feeds and well, anti-normalcy. They're a bunch of weirdos and they prefer that. They don't want non-weirdos in their feeds. They don't want any feed but the chronological one.
If they want to make Tumblr easier to use, they could make it easier to link to a dedicated post without logging in, but the last change they made made it so when you click on a user who has reposted it takes you to the user's main feed rather than the post. So I don't think they understand this.
So instead they add all this shit like "Tumblr live!" and commit the unforgiveable sin of suggesting an algorithmic feed and just piss off all their current users.