He really, really, REALLY isn't, actually. What he is is kind to everyone until the first time they break their word, or otherwise betray his trust. At that point, he treats them like they're completely worthless, just like they're a Hyuman, because at this point in time he really has a serious racial bias against Hyumans in general. Furthermore, he really does want oh so desperately to keep the demiplane as his refuge where he can get away from all the stress of pretending to be what he isn't and just be himself, so he is acting a lot more relaxed in front of them while they're inside than he would outside. Would you want to be able to keep relaxing in your home/man cave/bedroom/wherever you have as a retreat from the world, or would you rather treat everything as if it's the outside world and you need to keep yourself stiffly aware of all your actions and words at all times? I know I'd definitely choose the former, too.
Nah, its entirely their fault for treating everything as if its owed to them just for being Al-Elemera (or however it's spelt) and the king holding stubbornly to his pride and refusing to apologize.
I mean, the thing that you have to take into consideration is that a (unfortunately) large number of people
always react negatively towards
any main character, or even sub character, that isn't immediately bloodthirsty ruthless and immediately and only resolving problems through violence. They assert that any act of diplomacy or sociopolitical move is weakness and any act of kindness is heresy.
The number of times I read the comments of manga (Isekai or otherwise) where the MC reacts with something other than immediate murder or torture and they
freak the [bleep] out is nearly immeasurable. It's, frankly not only disturbing, it's disgusting.
Hell, I have had to explain on a number of occasions how the (apparently) expected response would ultimately lead to the either immediate or very rapid end of the manga. Such as: MC immediately responds with violence; regardless of murder or not the local authorities try to arrest them; MC again responds with violence; the national army tries to eliminate them; the MC responds with violence; other countries band together to eliminate them; MC responds with violence; all sentient beings in the world are eliminated (not conquered, eliminated); the local God(s) finally take action and try to eliminate the MC, who responds with violence... Universe ends, MC dies. End of manga.
Or, worse, MC responds with violence, local and national authorities decide that those MC cared about are
also a threat and eliminate them while MC is busy murdering... MC therefore becomes responsible for the deaths of those they would have tried to protect, because they responded with violence as opposed to trying
literally anything else.
But, no... violence and "alpha male" MC is all these people want...
Please note, this, as a whole and in its totality, does
not (necessarily) represent the person you responded to, but their comment still reads like those "others."