Please look around. This has been discussed to death for years: https://itch.io/t/160014/can-i-use-exclusion-filters
You mean the way you can add something to the URL to exclude a single tag... you know when it works?
Yeah what a spoiled brat I am for wanting one that's easy to use, works consistently and can exclude more than one tag. Clearly this is an insurmountable challenge of UI that is far too difficult to add. Ignore how someone made their own site that does just that
…In that case, perhaps you should be more specific. There is, in fact, a more capable solution made by redonihunter here. Hope this helps: https://redonihunter.itch.io/itch-browse-tag-exclude
there is genuinely no reason not to have it
There were no reasons stated, as far as I know.
So it is all guesswork.
The simple reasons are of course, it costs money and will only benefit very few players. Steam has negative filtering and a very limited tag number. I never felt the need to use it there, apart from analytical experiments.
There are over a million games on Itch and negative filtering will not reduce that number much. Filtering away 80k horror games from 1.45 million will still give 1.37 million games. Filtering positive will do that much better. Do not want visual novels? Look for what you want. If you like platformer games, use that tag. There are not many platformer visual novel. Oh, and there are still 500 of those. Why did they tag visual novel? If it is a platformer game, it is not a visual novel. Just because it tells a story, does not make it a vn.
So maybe the main reason is, that tags are not accurate to begin with, to use them for negative filtering. Sure you could filter tags, and a single tag exclusion was implemented quite quickly. 8 years ago. Itch has 8 years of user statistics how and if people would use such a feature.
It will not help you find games you like. But it would hinder you to find games you might have liked.
I picked a game rather randomly from the list of platformer visual novels.
https://intoadream.itch.io/into-a-dream
Tell me, would you consider this a visual novel? It would have disappeared from your browsing, if you would use a negative visual novel filter.
No one claims, it is impossible to do. And a single filter was implemented in a day or so.
The problem is not the filtering logic itself, imho. That external site would break down, if it would receive the traffic Itch receives. You do not know the server load a search query causes and you do not know the difference in server load a negated search query causes in comparison. That you need to be logged in to be allowed to use the single exclude query, speaks volumes to me.
Itch's system under the hood is obviously optimimsed for overlapping positive filters. You can't simply overlap a negated filter with the same system. Not if you build nightly lists of those things, to prepare for the querys. They would probably have to build a (all-x) filter for all tags. And there are tags that have like 5 items. They did this for the no-ai tag.
You know what breaks down first, when Itch suffers yet another ddos attack? Browse filters with several tags.
I can simulate multiple tag exclusion on Itch. Client side. Takes a few minutes to set up, depending on the tags, and works flawless. But it does me no good. It's useless to reduce the clutter on the front pages. Oh, trivially, we could remove most games on page 1+2 with 2-3 negative tags. But is that what we need and want? Do we really want to look at "popular" games without a tag preference, but remove the actual popular games? There are far too many games for that. And the tags are just not good for negative filtering anyway.
Most people seem to care for the top pages, and what we need there is not a tag filter. It is an hide-this button. With filters you will visit next week again and the same clutter that was not cought in your filters will still be there. Plus you will filter away games that you might not have wanted to filter away.
