Those marketing types might not be the best to judge how players chose adult games. Do not forget that you do not compete against all the rpgmaker rpgs or the non porn vn. There are not thaaaat many porn games, once you narrow some tags down. I can easily hover over most of them and non appealing screenshots are a turn down.
Also I find it suspicious. they think that your title and capsule would be the 1% kind, but did not provide the 3% version. Is your plan to come up with a new name and capsule and ask again how much conversion it will give, or just hope, you picked a 3% version and not a 0.5% version.
Did they use any repeatable metric to prove that "Tainted" and your capsule is a 1% conversion title? It is hard to test, even if you would change your capsule on itch. You are already known to some players and that might invalidate the results of any test here.
You do not see porn by accident. And I do not know if Steam promotes porn games in their shop page or recommendation lists.
The main thing, imho, is to make clear from first glance, if your vn is japanese hentai or realistic looking. Fresh Woman and the other is cute puppy eyes and looks non fantasy slice of life. And just look at the game page of the fresh game. Slices of different women on top ;-) Also both do not sound inherently lewd to me. And the other one even has a non searchable name, it is written as dik, but that is a delta. (Yeah, it is a word play)
I do not know if a fantasy setting is a good or a bad thing in terms of target audicence, but I guess it is an inherently weak thing. More people like to watch telenovelas/drama than fantasy genre. And that translates to porn games as well, I would think. Fantasy is more popular in the last decades, thanks to LotR and GoT.
But slice of life drama with porn is just appealing to even more people. They do not need to learn the lore of the setting to understand everyday life porn. Of course, if you show slutty Lilith with cleavage, you will absolutely peek the interest of players looking for adult game and liking fantasy content. But she is not in the game for quite a while, from what I deduced.
My naive plan would be to gather initial fans by promising exactly what is inside, so they are not dissapointed and leave negative reviews. And of course by having a good game. From the little info I have, that would be the sluttiest puppy eyes the main female has in the first chapter and maybe a title that hints at the fantasy setting, but not too much.