Well, he clearly respects J, however he does not respect the person behind the hero. Mc is uncomfortable with everything going on, I suppose this is going to be a romance where they keep bickering from time to time. But in my opinion ML is too immature to even understand how his actions impact those around him.
I view the MC as a metaphor for ptsd and the depression that results from that trauma. The MC is J, and J is the MC. ML and MC are both searching for J throughout the series. ML is obsessive about it, sure, but he sees and loves J with and without the mask more than anyone. So much so that he will do whatever it takes to see him whole for once. I hope that you continue to give him a chance!
I'm still reading this, bit the ML really lost it for me when they cut his apology out of the Manga. In the novel, after the dungeon where Seo reveals his identity, Kwon appologises for everything he's done and said that have upset Seo (and me as a reader). It's the start of visible character development for him. I'm really disappointed they cut it from the Manga bc it leaves him feeling immature matched with Seo's over-maturity.

Read until chap 52, ML is still pissing me off, does it ever get better?