@MattScott Restocking ammo is not a fun or engaging gameplay mechanic. It is needless and tedious busywork. On top of that, you still purchase and resupply from any ammo supplier (vending, spawners, boxes, etc) so there's no real excuse to not also do so from death on respawn.
That tiny and vocal minority that wants to waste their time buying ammo after every mission can still do so, but don't foist that garbage on those of us that value our time and energy.