This kind of thing was one of the reasons I changed the default, I never understood season length to imply some kind of general time dilation.
It is, totally, but see below.
I think you mean unrealistic fun and realistic not-fun?
I think we can bridge that gap with various features.
I disagree, a broken bone WOULD be essentially game-ending to a starting player, but that gives you a reason to stock up a base with supplies to wait it out. If you’re well equipped enough, it would just be a time sink, and with the right setup, “wait out broken bone mending in bed” could be less than a minute of player time, so why not make the timescales reasonable?
Not TOTALLY pertinent here, but this is the direction I plan on going.
Awwww, you guys preemted my reveal 
I plan on making this the official lore, that the super healing speed is a universal trait acquired by blob-infected survivors. That also opens the door to things like some mutation trees potentially losing this ability in favor of other things, and potentially an ultra-hard “pure human survivor mode” where the survivor does have only human-normal traits.