Right, and you think the NTF wouldn't also be inclined to destroy anything they couldn't hold? (likewise GTVA; I mean, you'd like to capture installations, but if you can't, then first order of business is to deny them to the enemy)
Where would they get infinite military rations from? I mean, I doubt the GTVa has a few hundred million packs lying about on the offchance of a supernova.
And it's all very nice the military taking on xxx thousand people but a) that's not going to go anywhere near solving the problem b) they need ships and training locations to be replaced, both of which take time and money and c) they also have an existing recruitment to consider anyways
Oh, and d) there's an issue of budgeting for new people. They might not be paying the dead - assuming there's no combat insurance - but they still need to replace everything lost with them by way of supplies.