I think you have to be pragmatic here and not do anything that might appear to be cutting your nose off to spite your face. If you refused to fly on an airline because they treated you with contempt then you would be going everywhere by train. You have paid for those miles and not 'spending' them on BA services instead of using hard cash is exactly what BA want you to do.
We are not great fans of BA at all, but we have >500k miles in our household account, and they are worth money. So we have started using them for late bookings within Europe. Even with their deceptive fuel surcharge they are now almost competitive with the Locos on last minute flights.
You can also put them in a household account so family members can use them if you don't want to. Or just use them to buy tickets for other people.
I certainly wouldn't throw them away.