Actually the points Sir Nick made are, in essence, valid.
There is a large difference between the people in First and Standard Class - that's simple economics, almost all FC passengers are business people who are paid for by their companies. The comapnies pay for a smoother quieter ride in a better sprung and upholstered seat, allowing their employee the twin benefits of being able to work in peace and quiet, and arrive not feeling like a wrung out rag, and therefore ready to be productive, so it's a worthwile business expense.
Sir Nicholas makes the point that Standard Class is noisy and full of children, and he would get no peace, or privacy, which for an MP is important BUT ...
being the rabidly snobbish upper class twit (sp?) that he is, he inferred that people in Standard Class are inferior and badly behaved, which from an MP, who is voted into office by those very people, is an outrageous slur on the tax-payer / voter at large, and he has been rightly dismissed as a right-wing fuddy duddy who is on the way out.
I believe that the day an MP gets First Class Travel between his / her constituency and Westminster - Day One - is the first step towards estrangement from the people they represent who cannot afford the luxury of such travel, however valid it may be.