I was responding to
@Flamestrike and his statements about how crazy some 'murderhobo' is (and presumably this was directed at the PCs in the OP). So, my response is "all PCs in this sort of game are already stark raving mad." I think backed that up with some more statements along the same lines.
I have no idea what your games are like, I wasn't commenting on them, and I'm perfectly willing to believe they have a different tenor.
Again, there's no implication in anything I said that YOU
@Oofta run a game which is structured in the way I described. I have no idea if it is or not. At a guess I would imagine that the PCs in your game are FAR from normal average people, and probably do some things that most people would consider a bit crazy. OTOH that doesn't make them completely nuts, there may be well-established reasons. And its always possible the characters in your games are simply well-adjusted normal people I guess. I try not to speculate on things I don't know...
lol, I made my money for D&D books fixing lawnmowers as a kid. I can believe it. My friend and I once set ourselves on fire, luckily nobody actually got hurt in that incident, but I guess lawnmowers are kinda evil!

As for 'first responder' types... First of all, they're not much like PCs at all, IMHO. They get paid to do a job that is moderately dangerous sometimes. However, they also take very careful measures to mitigate all that danger. I remember a huge 5 alarm fire burned a whole city block next to my house when I was a kid. The fire fighters did take some risks, but when it was obviously too dangerous the captain got on his bullhorn and literally said "I'm not losing anyone, EVERYBODY OUT NOW!" and then they stood there for 5 hours and watched the whole block burn. These are people who understand the difference between doing a job that involves some risk, and being a nutcase.
In the case of soldiers, it requires strong discipline and motivation to create a fighting force. I'm no military officer, I can only note what I see, but what I don't see is anyone taking a risk they don't feel is needed or justified. PCs might potentially fall into that category, but IME D&D is not great "out of the box" at portraying this kind of situation, it just doesn't set it up. As I said in another post, games like BitD are much stronger in this regard.
Every soldier in history went into battle to 'protect his people' if you ask me. I think this is a complex psychological question, and actually IIRC the US Army has done a huge amount of research on it. I'm no psychologist or such, so I can't really comment much on what they found, though I do remember that the US Army determined that in WWII less than 10% of all soldiers EVER fired their personal weapons at the enemy in battle. Even soldiers, probably believing in the rightness and necessity of their cause, are rarely able to bring themselves to kill. I believe almost all the cases where they do so were outright self-defense or defense of another fellow soldier in their proximity. Even in Ukraine it appears that 90+% of all casualties are caused by indirect fires, that is people just operating a machine nowhere near where their targets are.
I wouldn't presume to know all of what people play now. I have read some APs, they seem REMARKABLY similar to the DGQ series from way back in the 1970s to be honest. Yes, at the start of D1 there's a bit of setup that says the PCs are wiping out the giants because their homeland is being raided or some such. Its a single paragraph, maybe 2! Next you are plopped down in front of G1, which is basically a dungeon, albeit half above ground, filled with giants. I don't see where any of the 5e APs are much different, and my assumption is that the vast majority of play is published adventures, or stuff modeled on them.
Again, I'm not commenting on your game, I was responding to Flamestrike. I think it is a reasonable response, the average D&D adventurer is at least a pretty abnormal individual. I don't particularly find it easy to relate to those sorts of characters very easily. So, for example my Stonetop character is a young woman who has experienced some weird magical effects, and is very curious about them, and is trying to locate her missing father. She's part of the community (she brews the whiskey for the town) and is maybe not your average person, but she's not super weird and abnormal. Next session she's going to (I assume) go along on an attempt to rescue some town children that are in danger. Beyond the obvious 'civic duty' motive, she's undoubtedly curious about the strange forces which seem to be at work in this kidnapping. I can relate to this character, though some of her life concerns and such are probably a bit foreign to me.