Likely just a difference in preferences.
Like I said, I also get the feeling there are just typecasted chars in the game instead of characters and drama overkill just to keep things slow. There is actually no reason within the game or the characters that means bro and sis could not have slept together in the very first episode if MC just would have admitted to remembering the promise.
Now we all know that first at least 4 or 5 unnecessary drama plots will have to be taken away before they will, but that has nothing to do with the characters or their story. Too many unneeded blockers instead of real development, where the BF and the GF are two major examples of and neither plays a real meaningful role in the game. The GF is just a bit more loving and better looking version of the father and Brody ....... It is like watching a soap and getting back to it three years later, all kinda things have happened but nothing really happened except the chars are three years older and you missed nothing and can get back into it in 5 mins.
Edit: It is a bit like with DMD, if you played the first half of chapter 1 you can basically just stop and download chapter 3, set the correct points and go on with the story. You will have missed nothing except some hot sex scenes with others, all the story and developments inbetween are just filler and fluff though. Some people do love it though, others less.
