As someone who is vaguely the subject of this thread, I'd like to respond. There's not really any way to make this seem non-confrontational, but I will try my best.
The answer to the OP is "a lot of people left for places which require less effort to post there. You can find such things trivially, but most of those people seriously hate ULMF, and would rather not have their sites mentioned on ULMF." You should make an effort to find other places which discuss hentai games, and you should try to do it through channels other than ULMF.
I believe that people don't really "leave" the forum if they were only interested in the H-Section. The typical person who uses ULMF for h-content is mostly there to take and not give. The new rules have made it so that they have even less incentive to try to post. But they still benefit from the people who do take the time to produce content or information, so they don't actually leave; they just lurk.
This is true; the issue is that the typical person who uses ULMF for h-content being "mostly" there to take and not give doesn't exclude them from occasionally contributing. People who lurk aren't necessarily just leeches - they're occasionally worthwhile contributors. Discouraging them from posting creates an environment which begins to grow sterile, and encourages small contributors to contribute elsewhere. This in turn causes people to lurk elsewhere...and the cycle feeds itself (up to a point). As there are other sites where the information contained in the big contributions can be gathered (
You must be registered to see the links
for instance, if you can read just enough Japanese to understand the tags), ULMF becomes sort of a worthless place to go for information.
There's a secondary issue where it's forbidden to ask for download links. Although I understand the reasoning behind it (it is annoying to see a thread bumped with "link plz"), in some other places asking for a download link prompts someone with the game to identify that there's interest in the game being posted and it makes them contribute with a download link. This in turn drives discussion about the game, as more people have the game now.
In short, you've burnt the small contributors off, while large contributors are often contributing elsewhere. ULMF has no forte.
Want to find out about new games? Just go on DLSite, nobody talks about games that aren't on DLSite here.
Want to ask for a download link? Check on [catsitegoeshere], you're probably covered.
Want to discuss a game that's not being discussed? Spend 30 minutes making a thread or go on [any forum with lower posting standards]
Want to discuss a game that's being discussed? Well, [any forum with lower posting standards] already has a roaring discussion about it, and they're all having fun.
The remaining 30% is the unfortunate part. They probably read the rules, and still made the decision that it isn't worth coming to the forum anyway. And to be honest, I don't really blame them. The rules were made to keep the low effort posting to a minimum, but because of how strictly we've enforced it, it's made the lives of those who've done nothing wrong harder.
The rule changes are something that feels "sort of old" by this point. A lot of people - myself included - feel as if starting a thread for a game that they want to talk about on ULMF is "hard enough to do that I don't wanna do it if I can do it somewhere else." ULMF has developed this reputation and it would be exceedingly difficult to shake it. Compare this to, for instance, ULMF 10 years ago where you could just start a thread with an image and the name of the game, and say "I like this game, here's a link to the DLSite and a picture." Someone might have said "give more details" and if there was interest, you could edit the OP later while discussion was still able to continue. If there was no interest, then you hadn't wasted much time talking about a game nobody wanted to talk about.
I am reminded of a semi-recent case where someone wanted to start game discussion in a translation thread. The game's thread was locked due to the OP being made poorly, and the poster didn't want to create a new thread for the game, as creating a new thread for a game takes some effort. The rules were enforced, and discussion was effectively shut down. I am not sure how common this situation is, but it is common enough that a casual lurker sees it. The rules are enforced extremely strictly, and sometimes without regard to common sense. The automatic and mechanical enforcement of the rules creates an impression that the mods are acting robotically, and that they are either autistic or actually robots. This shuts down conversation, in a very direct manner.
The rules here are overly stifling. For this reason, I don't come here if I want to start a discussion about a game that isn't already being discussed here. I haven't made a thread here in years, I think, and I contribute only when I think the contribution won't be posted by someone else (a save file for a hard game I have beaten, or an answer to a question).
Well, honestly alot of people just stopped coming. Don't know where they went and there are probably a number of reasons why. One of them may be that F95zone is a thing. Maybe they went there?
People have the impression that this place is trying to become a second F95zone, and there are people who have left for that reason precisely. Given the current rules structure, ULMF is best described as "F95zone with fewer features." A chunk of lurkers stopped coming because links are hidden to people who haven't logged in - people who don't stay logged in to ULMF (for instance, those whose cookies are set to auto-wipe upon closing their browser) find this annoying. People don't bring these things up here because either they don't care or think they will get banned for bringing things up. Those who do bring things up like this usually are acting as if they don't care if they get banned - often because they do not.
I understand that it may seem silly to write such a long post on this topic when my key complaint is "it takes too much effort to post here." However, my complaints here are not really my own - they are the complaints that are repeated on other sites constantly, and it seems in poor taste to keep them to myself when this is in fact the one place that they need to be heard.