My drawback for absolutely NOT "resting at every fight" (fun fact: more than 10 hours into my third character I'm exploring the spider caves under the village and I have yet to rest ONCE) is that it would be fucking boring and a tedious waste of time.
But hey, I'd be all for enforcing some restriction.
Except developers probably don't want to even attempt that sort of mechanic or they would be SIEGED by Kotaku and all the gaming press of people who can't play decently to save their life would cry about how elitism and gatekeeping are preventing them from having fun or something.
