It's nice that Dating my Daughter has sharing content and even dedicated options that lead to that content but one very important thing to note is the fact that the game is very dense and not entirely in a good way. The mechanics the dev chose aren't really player-friendly. The walkthrough just for the first chapter is 30+ pages long which you pretty much have to follow because you can miss on some scenes, which you won't be bothered to get later since the game series is so huge.
As eloquently put by a couple of users in the review section of the game, particularly
Joey's Conscience: The focus is too much on things that don't matter ultimately and the game has a VERY slow buildup, if you can get past that just to get the sharing content then go ahead. I personally don't mind big games or even games with a slow buildup but I absolutely CANNOT accept playing another "Foot of the Mountains". There has to be another way of depicting a long standing relationship without using novel length introduction.
There's a walkthrough mod that saves you all the hassle so you don't have to constantly cross-reference a walkthrough document while playing the game and it makes playing it way easier since you just have to click on the highlighted choices.
While I do see where you're coming from regarding the length, honestly I've been playing the game from a long time ago (DMD was one of my first games on this site) without expecting any sharing content at all and was just there for the F/D incest so my experience with the game is entirely different.
Since I played very early on and played the game in bite-sized updates perhaps it made the relationship progression feel more "organic" in a way as opposed to playing through the entire content in one go and it didn't feel long for me at all as I didn't experience having to sludge through all of it at once.
So once they began to introducing sharing, from my perspective it developed nicely and it makes sense to be the next step in her corruption.
It's a matter of two perspectives I guess.
I could see what you mean for people picking up the game just now the content will be overwhelming, especially if the goal was to reach the sharing scenes you'll have to go through 3 chapters for it. So it might not be as worth it just for the two sharing scenes so far.
But for me the sharing scenes felt quite powerful as my attachment to Dee felt more developed and I've seen her grow from innocent hand-job only scenes to now this.
Maybe give it a few more updates when sharing path gets expanded even more, or newcomers only there for the sharing could directly download chapter 3 and 4 since they're standalone anyway and jump right into the content.