If corporate documents are instructing reps to tell customers it's about congestion when there is no congestion, that doesn't look good at all when the government starts asking about these plans and policies.
It's also probably not a good idea to be telling customers that the network you spend hundreds of millions of dollars marketing as super modern and awesome just can't handle their traffic.
I'm not a fan of caps, either, but aggregate home bandwidth usage is going to go up and up, while more and more customers are going to have everything they need from IP services and thus want to cancel traditional TV. Should you charge an IP customer who uses 4TB/month streaming 4K the same as one who uses 200GB? How else do you discriminate?