It's weird how so many always ship people when they fuck like rabbit in heat, they literaly dont need anything else to ship people in any story. I'm sure some will say "but Nanao love Asumi so much we saw her try her best..." TO FUCK MC.
It's been her aim for most of their relationship, she literaly cant diferanciate between her lust and anything.
If you look at all the girls in this story the "best" and "most healthy" relationship for MC would be to end up with Serina. She is literaly the one who has been the less weird and the most caring toward Asumi.
Some people are simply reading the manga and enjoying what they see on the page. Framing it as "shipping" implies that any intellectual effort was made, when in fact we are literally just reading the smut that was served to us, and going "that was very nice". Even if I didn't like Asumi and Nanao together, pissing and whining about them under every chapter would get exhausting after two years.
It's not my fault that Asumi has spent way less time on screen together with Serina than Nanao. I don't have the power to make them the official endgame, so I don't see what all your scolding is supposed to achieve.
But there is also something really ironic about lamenting that too many readers enjoy reading about all the sex the horny FWB pair is having, in a horny yuri manga titled
Asumi-chan is Interested in Lesbian Brothels! ... "Look at all these sickos, reading the smutty yuri manga for the lesbian sex. I on the other hand only read it for the plot, since I am normal.
"