If the planes are otherwise half empty, the potential customers aren’t paying cash. They are either going with another carrier or not flying at all.Re award seats, they don't want pax using ff pts when they will pay cash. With ff seats they effectively already have your money.
All of those billions of un-redeemed points out there in the wild are a liability.
Releasing some award seats on an otherwise half full flight is a very low cost method of reducing outstanding points balances. And in a way that is linked to high customer satisfaction - it keeps your customers in the tent.
It’s a no brainer. Maybe their data analytics capabilities are not up to scratch.