That's the point. But how frequently do you get 4 men surviving a full engagement. Not a whole lot.
Pretty often if you are defending against grenades/flamers or other AOE (especially when in cover/garrison and using the LMG42).
Maybe this is a 1v1/team-games difference, but there are plenty of times (especially on larger maps) where the extra muni is worth it.
I mean, people throw grenades to deny the enemy cover and consider it worth it; why wouldn't it be worth it to heal up a squad that's battle ready and not have to retreat them + bring them back.