I don’t think the mc or anyone besides the receptionist knows how responsibility works. I’d get it if HE actually woke the dragon up or maybe got cocky and used a super overkill powerful attack that caused the dragon the wake up, but from how it was explained apparently the Wyverns woke it up and he just didn’t kill them fast enough (wut?). Had he done nothing and not taken the quest it would have woken up anyway. So he’s beating himself up over the fact that he couldn’t kill them in an instant (narcissistic much?). I don’t think anyone, but actual S ranks could do that (but even then how would they know to kill them instantly), and an that note the MC was an A rank meaning the quest was probably A rank or lower. Why not blame the guild for inadequate information? Had they known about the ancient dragon and made it S rank AND THEN he took it thinking he could handle the dragon it’d be his fault, but as is no one strong enough was gonna take the quest anyway. What was he even going to do if he got there in time? At best he could have saved some lives. There was no way he could defeat a S rank raid boss, and even if he could I don’t care how strong he is, he wouldn’t have been able to defend everyone AND fight the dragon well enough to defeat it at the same time. You don’t blame a lone firefighter for not being able to put out a wild forest fire. Actually maybe blame whatever idiot decided to put a village within walking distance of a freaking Volcano.
Ngl, the entire beginning sequence seemed so silly, I thought it was purposely trying to be a FATE parody/reference.