Good post. I think people ignore the mid-range market, in places like this anyway. The ever-increasing-detail route suits the mindset of forums devoted to oneupmanship & pursuing specificity vis-a-vis tiny details, that no-one much notices if you don't tell them.
I've started to admire some of the fantastic 'cheats' done by model companies in the past.
The model that broke open American N gauge as a viable scale, is wrong, if you want to think about it. But seeing as it was such a good runner, and took tooling to a different level, no one noticed.
As for Hornby, if they see TT as a way of not having to go down the superdetail road, due to the smaller size, and the fact of high speed requiring more space, in an era where houses are getting smaller, that's good too.
And I guess high speed trains, since they have to be kinda sleek, have less tetchy detail bits on them anyway.
I haven't seen a Southern Pacific-style headlight arrangement on too many Chinese high speed trains ;-)