The purpose of the arrangement you're pointing to is so that transit providers (e.g. Level 3 or Cogent) could distinguish other transit providers from transit customers whose traffic was characteristically asymmetric. The reason transit providers care more about upload bandwidth than download bandwidth is that customer ISPs can easily offer web hosting services to balance their traffic load, so it would be fruitless to charge the ISPs more for not sending the transit provider more traffic they have to carry. Better to give the ISPs free transit than that.
But Verizon isn't the transit provider here, they're the ISP. By sending Verizon a lot more traffic than they receive, Level 3 is effectively offering Verizon a huge amount of free transit in the other direction. That's like free money. Verizon could trivially use it to out-compete AWS on bandwidth pricing and make a boatload of easy cash. But that wouldn't unbalance the playing field for competitors of Verizon's video services.