Why doesn't respawning cost nanites?

lets say the infantry spawn is limited to the base-nanite-stockpile. maybe in the future ants are needed to deliver nanites to the base. what happens if the base is besieged and your little nanite-sundy is unable to reach the stockpile? the base would be lost at the moment of enough enemy power in the area. i can see the days where air force is hunting nanite-sundis the whole day. big frustration incoming!!

How about infantry just can't spawn without enough nanites?

NERF INFANTRY!

Spend nanites to lower your spawn time.

Want to get into the fight 2-3 seconds faster? Push this button, it will only cost you the same as one grenade.

Oops, no nanites? regular spawning for you!!!