It's not just the way I see it, it's what they admit too in the scene at the end of episode 4. Then they dump you if you're a DIK. It's not just opinion, it's what's in the game. Why would MC be friends with these two? It's the biggest flaw in the game as far as I'm concerned.
The DIK rejection thing is messy, I agree. They do the same pleading for another chance on both paths and it very much seems like they want a relationship with the MC, which is why the rejection comes as such a shock. This is why there shouldn't be a rejection path and it should be just a friend path and relationship path, only it's the MC who automatically choosing friendship on th DIK route.
It's not that easy to just brush rejection aside and be friends that quickly, if ever, but if
you choose to be just friends when it seems like they wanted more, then you're essentially telling them that you're not sure you want more, so the onus is on them to try and win you over, hence why they try so hard to be your friend.