ok so he's not the BEST main character but he isn't a bad one either. a bunch of people are like ohhh he's so sentimental and he cares too much about demons yada yada yada he cares more about a man he just met than his dead family
first of all, when he first found his family murdered, he didn't have time to grieve because nezuko was still alive and he wanted to save her. he hadn't known that she was going to turn into a demon when he had first found her, so it was his biggest priority getting her to a doctor.
and yeah, he cares about demons and sympathizes with them, but he still kills them because he knows its for the better. his way of giving mercy is giving demons who accept their fate painless deaths. his rage, however, for demons like akaza or muzan are unmatched and he really doesn't gaf about their story he just wants to kill them because they took people that were important to him from him.
tanjiro isn't like deku or emma - he doesn't try to find a loophole to save the villain. his goal isn't like deku's either - he isn't trying to become the strongest or defeat muzan, his number one goal is to turn nezuko back into a human. he just takes quite a few side quests on his mission. he knows that if demons that eat humans are left alive, then they will keep making lives miserable for families, which is why he kills them. if it was deku or emma they would've tried to find a way to peacefully live in harmony with demons 🤓
tanjiro is kind, caring, and sympathetic, but he isn't a cute innocent fluffy baby that needs to be cared for. he's the perfect mix of a protagonist with a kind but strict heart (like a mother). he isn't focused on trying to rewrite the system so that all demons can live happily. he knows that nezuko is different from the other demons because she doesn't eat humans, which is why he's only trying to rewrite the system for her.
so yeah tanjiro isn't a bad mc. he's far from being the best, but he's a good one. An example of a bad mc would be deku or takemichi (i have a burning hate for both of them sorry not sorry) perhaps if tanjiro was in a story with a better plot, his actions could have been represented more clearly, but that isn't the case.
