But build a megaconstruction once and have some fun, build it a dozen times as mandatory part of the design of the game and you'll find yourself bored or frustrated. Thus the simple, bare-bones approach to not freezing to death for the early game stages.
Excavating magmapumpstacks is more fun than harvesting wood or finding and mining out coal
Designating 100 z-levels of pumps? Idk man. Doesn't sound thrilling. But that can be said about pretty much any megaconstruction.
But you should have fuel lying around anyway, so that shouldn't be a problem. You can drop the fuel consumption of these fires to almost nothing, I don't care. I'm just suggesting this additional layer of realism, like many before me. It's not supposed to eat away your wood like crazy.
Speaking of fuel: Would someone consider embarking on a location without trees?
The thing is this: My suggestion should logically be applied to cold climates and glacier mountain ranges. These usually do not have trees, so there is nothing to burn.
This could lead to 2 conclusions:
1. The suggestion sucks, because if there is no renewable heat source, fortresses in cold, mountainous maps will become unsustainable in the long run. (Trading firewood maybe? Sounds pretty realistic actually.)
2. But thats the gist of it! The idea of embarking in a frosty, glacier map without any burnable material isn't sound in the first place, loosely based on real world experience.
Now since I'm suggesting this, I'm obviously in the second category, but i can understand either reasoning. I don't want to take anything away from regular players who have come to love their frosty, treeless maps, but it seems to me that heating is congruent with the current layer of realism in the game and should be implemented.
It's the one thing currently missing from the basic needs of survival.