I suppose that a name which ends with "...TV" arguably sounds too much like a channel/station/broadcaster in its own right, rather than a mere "programme on ITV". The fact that that's exactly what GMTV (and TV-am) originally was would be lost on 99.9% of average viewers, of course.
I don't think that the average viewer would have realised that GMTV (or even TV-am) was originally a separate broadcaster. Most viewers would have just thought it was a programme on ITV
All of which I have already acknowledged - In both the final sentence of my paragraph that you have quoted there, and also in the 2nd paragraph of my post which you haven't quoted.
EUropean. Gashead. Whovian. Grammarist. Pedant. Liberal. Ectomorph. Secularist. Vegan.