To be fair, because it's a sandbox, it's a lot of work to add when they have group scenes. You need to have pregnant and non-pregnant versions of each scene they are in for every character that has the option.The game premise is good but all these girls keep wanting raw sex and talk about giving them your seed etc only for there to be no pregnancy in the game.
Personally if it is not planned change the wording in game make MC infertile or something and make sure all the women know. Otherwise maybe think about adding pregnancy, you will entice a lot more players who love the pregnancy tags.
Just dont make it think like they want pregnancy but you dont add it
So, for example, you have a scene with two girls in it, you will need at least 4 variations of that one scene they are in together. Now consider that some scenes have up to 9 girls in one event (Class 4 sleep-over), that event would then need to have at least 81 variations of that scene to work.
This is why pregnancy tends to be end game content.