Other votes on the same issue:
https://itch.io/t/692147/is-there-a-way-to-exclude-or-ban-some-tags-when-i-brows...
https://itch.io/t/160014/can-i-use-exclusion-filters
https://github.com/itchio/itch.io/issues/475
https://github.com/itchio/itch.io/issues/738
https://itch.io/t/1457540/tags-and-genres-selecting-for-exclusion
https://itch.io/t/1355922/the-ability-to-filter-out-genres
It's the most upvoted issue on Github: https://github.com/itchio/itch.io/issues?q=is%3Aissue+is%3Aopen+sort%3Areactions...
Any idea if this will be implemented at some point?