Brady is not just some anonymous backbencher. He is Chairman of the powerful 1922 Committee, which means amongst other things that he is responsible for overseeing the selection process for any new Conservative leader. It is therefore likely that he would be a prominent advocate of the party line.
Another phenomenon we often see is that MP's whose constituencies lie close to airports often like to curry favour with noise protestors and eco-extremists rather than supporting the positive aspects of the business. Brady (to me) always gave the impression of being lukewarm about MAN. Maybe he is comparable to those London MP's whose constituencies lie very close to LHR or LGW, and in consequence vocally support development of the more distant option. Anything but more planes affecting my constituents? Wrongheaded, but not unprecedented.