Well, you don't feel that way, others do feel that way, yet others feel like you. It's all opinion. I myself am sorta neutral, since there are plenty of ways to mitigate this to some degree or another, both in and out of the game. And there's no real way to eliminate it completely, nor should it be done away with even if there was, IMO.
This doesn't mean the current situation is ideal, however.
For UFO maps and similar large structures you'd indeed need more space. Still, adding 20 to both map dimensions should solve most of such issues. Probably while creating some new ones, though.
How will the map be featureless? As I understand, if there's nothing on a part of the craft map, all the underlying terrain will remain intact. It will be enemy-less. And I guess also civilian-less, which is a bummer. But nothing like this flat desert you're describing.
For the last point, let me just say that I don't consider platitudes ('This is X-Com', 'X-Com operates' this way) any kind of argument.
Night fighting is another reason on top of smoke and 40-tile vision for why the current situation isn't going to change all that much even with an extra spawn-point-free cordon around X-Com craft.
I suppose a better way to do this would be to ask for a variant of the reinforcement-spawning command for map scripts that makes them only spawn some modder-defined distance away from X-Com soldiers. I imagine backporting that shouldn't be too hard. I'd still rather get the custom hangar code.
Come to think of it, you could actually make most enemies into 'turn 0' reinforcements and use that command to do a limited version of this change already. Hmmm...
But that would jettison so many actual map-building mechanics tied to regular spawning that trying to recreate the current situation this way is probably going to be madness.