To be fair, you have to have very high empathy to appreciate Steven Universe. The social commentary is extremely mature, and without a solid grasp of the importance of social justice most of the messages will enrage a typical viewer. There's also Steven's optimistic outlook, which is deftly woven into his characterisation - his personal philosophy draws heavily from Gandhi, for instance. The fans understand this stuff; they have the emotional sensitivity to truly appreciate the depths of these characters, to realize that they're not just inclusive - they say something deep about the human condition. As a consequence people who dislike Steven Universe truly ARE immature jerks - of course they wouldn't appreciate, for instance, the empowerment in Garnet's feminist catchphrase "Stronger Than You," which itself is a cryptic reference to Che Guevara's revolutionary last stand. I'm triggered right now just imagining one of those crummy Trump worshippers furrowing their brow in anger as Rebecca Sugar's true compassion unfolds itself on their television screens. What shitheads... how I despise them.
And yes by the way, I DO have a Steven Universe tattoo. And no, you cannot see it. It's for opened eyes only - and even they have to demonstrate that they're at least as socially conscious as me beforehand.