If i block adult content i block horror?
No. You block sensitive content. Deemed "nsfw" by either the developer or by staff. Only about 2% of the horror games here are marked as nsfw in my estimate.
If you specifically search gore games, select appropriate tags. Less than half the gore games are tagged horror.
And the "problem" with furry themed adult games are people like you. You shun it on other platforms, so it becomes apparantly more popular on platforms where it is not shunned. This is a similar mechanic like the apparant popularity of horror on Itch. Or the lgbt games.
So if you are here for the gore nieche, well, there are other non-mainstream nieches here as well.
Itch's content filter could be better, that is a given. They only have yes/no for content that is not suitable for minors or the workplace.