10 years ago I was catching buses to this school! We had 2 x double decker buses which was more than adequate serving Weston, Twerton, Southdown and Odd down. I also think there was 2 x 13C equivelant buses from Bathford. Overall, there was no problem. First seem to have cut back so much on buses and trains recently and I'm sure as you said it's all in the name of shareholder profits. And the government wonders why there's more cars on the roads...
I also think B&NES washing their hands of the issue is typical of their 'not our problem' condescending attitude, never accepting any blame themselves.