So tumblr is just a place to repost stuff you like?
Primarily, Tumblr is about using your blog to post whatever content you like.
It also allows users the option to repost the content of other blogs they like or want to draw attention to.
Naturally, as with all human endeavor, certain posts/blogs attract far more attention than others.
A feature of our species which allows us to form highly complex societies is that we are followers with a deeply ingrained desire to belong.
Tumblr, like any good social media platform, services this desire.
Hate it or love it, this is who we are.
Now, the wonderful thing about Tumblr, and the Internet, in general, is that you curate your experience.
You decide what media you consume and what content you produce.
If you don't like what you're seeing: block, delete, ignore, unfollow, unsubscribe and maybe even report/mark as spam if you're feeling especially vindictive.
It's entirely up to you.
I have 2 blogs that serve distinct purposes that, beyond me operating both, remain completely independent from each other.
Hop on Tumblr, find what you love, and create your experience with like-minded individuals.
In the words of a childhood hero: