Who's dumber me or DICE?

So, I am trying to complete the airburst challenge for support and for those who don't know you need to deal 500 damage with the airburst as support. Note that an airburst is a projectile that travels a determined distance and, well, bursts, dealing what can be described best as area damage. So this challenge seems simple enough. Shoot some rounds into a crowd and Number Go up, nope, not with dice they said what we are going to do is only count the damage from the initial impact and that damage will be 2 maybe 10 and that is only if it impacts the player. I just cannot get my mind around the decision making process here. How does this make sense. Can someone play devils advocate and make a case for this being done this way. I just see this and think these developers are stupid or lazy or both idk. I've killed 30 people today alone with that F'n weapon and I'm at 66/500