The spawn protection was added to help reduce spawn killing from other players and getting hit multiple times from the same airstrike. The current two seconds is just long enough to prevent being hit multiple times in the same airstrike and start running away from a spawn point however, I agree its annoying waiting for a weapon to come up or having to cock the weapon before you can use it during which time you get killed again.
The configuration can be changed to remove it, tweak it or we just leave it as is.