I agree entirely, as I pointed out in the earlier thread with the example of my mother, who is probably a fairly 'average' passenger in the sense she quite likes trains but isn't an enthusiast, and takes a handful of trips a year.
She'll happily get this when it is a direct service between Liverpool and Ely - she can get on the train, switch off, listen to some music, read a book or do a puzzle, and eventually she ends up where she wants to be, even if it does take quite a while. Bluntly, there's no way she'll do it if it requires a change at Nottingham. And if I suggested to her going via Leeds and Peterborough the response would be a 'why on earth would I do that' look and then a terse 'no way'.
I'm not suggesting that you would necessarily create this service as it is if you were designing the rail network from scratch. But the fact is it exists, has existed for many years, and people are used to using it. Breaking it is a very poor decision.