To GM4Him, All respect to your position, of course, but your reasoning is simply not sound. You're exercising a form of personal confirmation bias with the way you give your examples, and it doesn't hold true.
I can turn it around and show you what I mean, here, have a look:
You create a game. You want to sell it to 50 people in a room. Of those 50 people, there are 10 adults who like sex in games, 10 are adults who don't like sex in games, 10 are teens, 10 are kids and 10 just don't care. All of them like fantasy. I realize this is an unrealistic scenario, but my point isn't how real the scenario is. My point is that of the 50 people, how many are going to buy the game if there is sex in it? How many might you sell it to if there is no sex in it?
Potential maximum sales if sex is in the game = 20-30
Potential maximum sales if sex is not in the game = 50
Okay... set aside the fact that a game that is geared in a way that those 10 kids will enjoy is mostly not going to be geared in a way that those 10 adults will enjoy, and all of the other similar factors that influence the concept...
You create a game. You want to sell it to 50 people in a room. Of those 50 people, there are 10 product-purchasers who just want to play a fantasy game, any fantasy game (Group A). 10 who aren't specifically interested in sexual content in their games, but aren't turned off by it (Group B). 10 who aren't specifically interested in sexual content in their games, but give extra merit to games with sexual content (Group C). 10 who are actively put off by it, and require a very good product to purchase in spite of it (Group D). 10 who are only going to consider a game at all, if it has adult content (Group E).
So, in this scenario, a game without any sexual content will sell to groups A, B and D and MAY pick up group C IF the game is otherwise good enough – the bar is higher for them without that content.
A game with sexual content will sell to groups A, B, C and E, and MAY pick up some of group D if the game itself is good enough.
Potential maximum sales if sex is in the game = 40-50
Potential maximum sales if sex is not in the game = 30-40
It's very easy to set up an example that favours your stance, but it's not intellectually honest unless it's a fair example, and neither yours, nor mine in return in this case, are. Every kind of content addition both limits and expands your potential target audience in some way. Nothing is purely limiting, or purely expanding.
I just think this game is good enough without it. Therefore, it would sell more if they didn't include it.
That simply does not follow unless you beg the question of a lot of other underlying premises that you cannot take a given. In short, no, what you're saying does not track, and ultimately isn't sensible without a pre-established viewpoint that already agrees with it.
Putting anything into a game is a balance of the amount of people it will draw, versus the amount of people it will turn away; the rating a game has is an important factor in this as well. You do not, for example, count the pre-teen children as potential purchasers in your analysis when the game has a mature rating.
There is a target audience that would not have considered this game without the promise of romance and/or sex; people who glanced at it with disinterest and who only became interested when they learned that they were going to create detailed intimacy between the characters as part of the story romance. The question is simply whether the number of people who will try the game out when they otherwise would not have, with the added promise of this content, is greater than the number of people who definitely would have bought the game but now definitely will not, based on the promise of this content existing in it. We can all have an opinion on what the answer to that question is, but ultimately none of us has any factual data to provide that makes any answer certain. What we can say is that Larian and/or Wizards (probably mostly just Larian) have those figures and projections, have most certainly run the analysis and have, at least initially, come to the conclusion that the addition of it will improve their figures in the long run. They might be right or wrong about that, but at the very least they are in a better position to make that decision than any of us.
For the record: I'm one of those people in the group that really wants the intimacy to be done well, because as it stands, I'm not likely to want to play the game at all if it's not. The game itself is not good enough, as it presently stands. It's not a game I'd really be interested in playing, in this state and in this style, unless there's something to keep me here, such as solid romance and intimacy as part of the game's story.