DnD provide a rule set that can fit Lethal grim dark game, and Easy going kids and family game.You are making quite the circuitous route around the void in rest mechanics there. Players don't need to go anywhere or do anything during a rest & the returns on a successful rest are massive to the point where the closest analog is often on par with video game console commands/cheat codes. There's no bar they need to meet in action circumstance or support & no real chance of a death spiral. Players are given every reason to just shrug off any interruption like so.
When players do this it pretty much holds the campaign hostage. Players know the GM won't burn down their campaign with a TPK or throw out the adventure too many times to rebuild things if the group shrugs off doom clocks.
If you look back at past editions where players did not recover ALL hp, ALL ability score reductions ALL max HP reduction or have things like HD they could spend you can see classes that needed to actively do something* during a rest & didn't receive complete reset button results that obliviated death spiral possibility. Those meant that the GM had a credible leg to stand on when they said "you are in an area that you wouldn't be able to rest" as someone suggested the GM simply do through fiat earlier in the thread. That stonewall given to players is even reinforced with the continuation of short rest classes in this packet and an incomplete long rest that lasted at least an hour automatically granting a successful short rest.
* pray/study/provide care/get good sleep/etc from class to class.
It´s up to the DM to stand his ground and adjust the game to fit the tone and play style he want Or find a game with a mechanics that reinforce his specific play style.
it’s ok if you choose to make PCs dead as soon as they reach 0 hit points, but don’t hope the official rule to do that. the official rules will aim a vanilla middle ground tone. In need go listen some Dungeon craft video from The Professor, it will help tone your own game and take what you need from a rule set.