This is basically my answer in a nutshell
@Micah Sweet
I actually am playing a barbarian right now who was just in a combat. He had been dropped multiple times in the previous fight and we were moving into a new fight. He took the lead. Was I not taking the combat seriously?
No, I was. This combat was about rescuing a little girl who had been kidnapped. The two non-melee characters who were still up had much lower AC than me, but hit much harder than me. We knew there was only one, maybe two enemies up ahead, and my guy figured he could stay concious for at least one blow, and give the others the opening they needed. Could he have died in that fight? He didn't care. The point wasn't him trying to survive the fight, the point was the team winning the fight and rescuing a little girl. Dying was worth saving a child's life, that's just how he thinks.
Most melee front-liners I see are taking combat seriously. And to any degree they are incautious, it isn't because they are going YOLO, it is because they are prioritizing something else over their own survival. Generally the safety and survival of others.
Yeah, I know people give me a lot of strange looks when I say healing needs to be buffed, but frankly that would prevent yo-yo healing almost immediately. If you could heal and that healing at least cancel a single monster's attack, then you would see people healing mid-combat more. But very quickly they realize that taking their action to only partially undo an opponents action is a terrible plan, so all healing gets regulated to either after the fight or when someone drops and it is an emergency action.