If you want a better CW seat BA provide First.
I recently flew MH on slopey seats. I was amazed by the openness and airiness of the cabin. Slept like a baby too.
BA provide a competitive product. I can't see how the much moaned about non issue of having to climb over someone's legs which are at most 40cm high is such a problem. And if it is, book an aisle seat. Want more privacy? Get a Window seat. Not agile enough - choose a different carrier which offers privacy and easier accessablity if you can find it. If you're too large to get through the gap then it's time for a lifestyle change or if unable/unwilling pick an aisle seat. Couple on holiday? Book the middle pair. Colleagues working together - book the middle pair. Parent with kids? Book the middle pair.
The great features of this cabin layout, offering multiple seat / space / access options aren't the minor point for everyone that many of the self centred wingers think it is. It is a strength.
So please, to those who don't like it, choose a different carrier. The seats probably won't fly empty and for the rest of us who do like it, this should mean we are able to book it more easily.