Lol, it's already needlessly punitive, a by a good margin.
And like More Badass asks, why wouldn't the player be able to quit the game? He bought the game. He should be able to decide if he wants to play in long 3 hour sessions, or in short bursts of 20 minutes each.
Why even consider that a bad thing? The mind boggles.
The primary theme of the game is that you are very low on a food chain in an incredibly harsh environment. Everything I've seen and played seems to be designed around the idea that you should be able to think quickly on your feet in any situation. If the player is simply able to quit at any point, this will inevitably lead to players simply quitting anytime a situation appears to be too difficult based on past experience instead of attempting to adapt in order to survive and continue forward. There is a massive emphasis on improvisation using knowledge about your environment, and the vast majority of that knowledge(along with skills necessary to put it to use) come from trying new things in the name of necessity.
The game is difficult, but that difficulty is what brings satisfaction upon narrowly escaping when it seemed almost impossible. Losing a level after quitting falls in line with losing one for simply not making it back to shelter because you were eaten or the rain came. It not only encourages the moment to moment experience that is so memorable, but makes each of those experiences even more memorable due to the ever present thought that you are only ever safe in the occasional refuge. Personally, I have more awesome memories in my short time with this game than almost any other, whether between finally getting past an area that always destroyed me, or because I only narrowly escaped the rain by swimming under the turbulent flooding in the room of my nearest shelter.
I don't agree with the line of thought that it should be removed due to it's punitive nature simply because almost every enjoyable part of this game relies on the punitive qualities of the world. My only problem with it is that it should be communicated before the player is able to quit and unknowingly lose a level.
Besides, losing a level just isn't that big of a deal, at least it hasn't been so far. Getting the necessary minimum(if a cycle is uncommonly harsh) is a priority and you can simply hope to make up for it in the next cycle. There's no problem with simply grabbing food and returning within the span of a few minutes, should the need arise.
The fact that the player bought the game does not mean they have a right to quit without consequence. They bought a product without even knowing if they could enjoy the experience without spoil for any particular design. When it is imperative for the player to learn through difficulty with the world, I only see quitting without punishment as something that dampens the overall idea that you're a weak creature in a world that is alien even to itself. If you can't take the 5 to 10 minutes maximum required to find food(if you are at 0), then just take the hit and continue the next time you boot up the game. In my opinion, the small inconvenience is worth an incredible amount in the name of thematic coherency.
On another note, the comparisons to dark souls are somewhat innapropriate. The only real similarities between them are that they have a certain amount of an open world that is used as a vehicle in order to tell a narrative that can be nearly completely ignored, they both promote feelings of isolation, and they use difficulties that must be overcome without much guidance. They share a similar thematic core, but Souls has always been about progressing via your avatar using RPG elements, and there is very little in the way of variance provided by procedural generation/guided RNG. Although, if the discussion needs examples of similar approaches to player experiences, I suppose it is one of the only common examples in the industry. Rain World resembles Dwarf Fortress far me to, at least in concept and what I've taken from all three games.