I blame the architectural community at the time. It was riddled with middle class snobbery. If Villa Park had been a theatre or a railway station or law courts there would have been a nationwide outcry at the loss of part of our Victorian architectural history. But it was only a football ground populated by the great unwashed who kept coal in the bath.
The problem they had with the new stand is the lack of space to do anything impressive from the outside, as it goes over the road. Perhaps towards the north stand they could have included some red brick design as they have with the back of the Holte. Perhaps they still could, its all for show and wouldn't be structural.
I'd like the corners filled in and the roofs connected.