I just wanted to get this out there, maybe have a discussion on the matter. How bad can you design a game, that the most popular mod for your game is a way of making the experience not suck ?
Why expect that a walkthrough mod is necessarily used to make a game not suck ?
Most regular games have a walkthrough, that can be useful when you want to perform a certain task. "How to befriend the Legion in Fallout New Vegas" ? "Where are those fucking interface in System Shock" ? And so on.
Even on the adult scene, there's games that need you to be careful to the small details in order to achieve the "perfect score" ; don't be careful enough, and you'll miss the harem ending. Take
Summer Scent by example. I wonder how may players are frustrated right now because they hit the bad end that came with the last update, or have had their MC ass raped. If you think about it, it's not difficult to avoid those two situations. But it's also really easy to miss the two/three choices that permit you to not prematurely end the game ; especially since it's an adult games and you need to not focus too much on the lewd to make the right choice.
Because it's something that need to be remembered, it's adult games. A lot of players just want to see the goods. And like they don't want to miss a single part of them, nor have to think too much, they use a walkthrough whatever if it's really needed or not.
In the same times, too much games have a so bad design that you end expecting the same thing from all games, and therefore tend to not take the choices seriously enough. There's a harem possibility ? "Yeah, I'll pursue all the girls then". Well, too bad,
Summer Scent is a game that expect you to make the right, and logical, choices if you want to have the harem ending. If you play it like any regular shitty harem game, you'll end with a dead body and a girl too depressed to care about your existence.
There's also games like
Super Powered, where you can easily miss part of the content. Not because the design is bad, but because it offer too much varieties and its too opened to the player decisions. There's some design flaws, partly during the quests where the player advance a little too much in the dark, but it's a really small part of the reason why a walkthrough is needed for this game. The main reason is because it mimic too much real life behavior ; scenes don't happen without reason, and those reasons are a combination of different factors.
If you don't know what Nikki's Fetish is, you'll never see the scenes where she's involved with another girl. And it's normal, it's supposed to happen like this in real life. You can't try to turn this into a threesome if you don't know what kind of girls she can't resist ; and this second girl can't be Allie or Chelsea if one isn't actually turned into a sex craved nymphomaniac. Like you can't fuck Nikki as a male if she's not herself turned into a totally sex craved lesbian.
All this is logical and feel totally natural, but you can easily miss those scenes if you don't have a walkthrough to tell you that they exists. Then the way to see them will seem obvious while you follow the instructions, but what you needed, what you expected from the walkthrough, wasn't those directions, but the knowledge that those scenes exists.
And all this lead me to a conclusion at the opposite of yours. If a game don't need a walkthrough, then it probably have a shitty design. Whatever because the choices are way too obvious, or because they end being totally useless.