Yeah, the rutheless route gets a bad rep for it's implications. It actually expands the lore in a scenario that couldn't happen in the "good" routes. Honestly, i believe the advertisement is just too off putting for people to give it a chance, but it really isn't about being evil to Asterion.
Ehhhhhh, you're taking someone that is very obviously traumatized right now and heaping more problems on top of it. Deliberately causing a panic attack with your ordering him to come join you to eat is really shitty and kinda evil in my mind. And you're taking the one good thing Asterion had, the hotel, and turning it into its own form or torture with how closely you interact with him in all the commanding, ruthless ways.
If there wasn't a narrator and we didn't hear into Asterion's thoughts, it's easier to dull the empathy and just play the mustache-twirling villain MC to see the content. But that's exactly the point the VN is making in the normal route, that you're doing basic human empathy to Asterion and he thinks you hang the moon because of it.
I don't disagree that it tells a fascinating tragedy if you go down it, and it shows a lot of things that couldn't be told if the master of the hotel was good, but it was still really rough and I'd say evil, personally.
Oh, what i mean to say is that it's not "about" being evil. It happens, yes, but most of the route is learning Nikos background and motivations, along with aspects of the labyrinth and the divine beings. Plus, i was expecting MC to be relishing more in Asterion suffering, yet it felt to me like MC just didn't care about him or anyone. Then again, this opinion is due to a contrast with expectations, which are subjective.