>>283185795
>I honestly have no fucking clue and I feel like it will be the most unsatisfying reason ever once they explain it.
It has been explained, you just don't believe the reason because its pretty dumb. Now, part of it is almost certainly going to be a level of him being fucked in the head by Satella so he automatically likes her clone and that bit hasn't been explained, but when it does get brought up I bet its going to be argued as not that significant or not the primary reason for him being like that.
Starting at the most shallow you have her appearance which is his physical ideal. If he had to design a girl you would end up with Emilia. This is almost certainly because of his dick craving Satella.
Then you have him thinking he is owed a bitch by virtue of being the isekai MC, though this attitude gets beaten out of him as he tries to refine or come up with a "real" reason he loves Emilia.
She's nice/she saved him. This is his primary cope reason to not sound like such a creep when having to explain why he's following her to her or other people. The "she saved him" part is just pure cope because he wasn't in any real danger from the three stooges but he acts like she saved his life and uses that as justification to do stupid stuff. The "she's nice" part he tries to make more legitimate as his vague answer to why he even supports her in the selection or thinks letting a retard on the throne is a good idea.
A subtle part is him just clinging to her because he's terrified of being alone and didn't want to face that he might be stuck here and never see his parents again. This is also why he doesn't just abandon the mansion once he finds out Rem and Ram were killing him, he thought he was getting along with them and didn't want to give it up because he has no other fallback.
Saying he liked Emilia to Rem is also forcing him to stay sunk cost on that, since he considered that part of the "normal Subaru" she expected.