Post-Progressive

JS19 wrote: That's a lovely made up word. Words are only made up when there is an absence of a term for something. These bands are prog hence why they are in the prog archives. I'm very fed up of people trying to coin new names for them in order to have some degree of separation between them and classic prog, just for the elitists. Stop it. Now.

I don't believe the demarcation sought is designed to appease anyone, least of all those you deem 'elitists'
What we recognise as Prog circa '73 bears very little semblance to that which we recognise as Prog 2011. (Porcupine Tree or The Mars Volta don't sound remotely like Yes or ELP for the sake of a glib comparison)
The OP is interested in how that state of affairs came into being and posits the perfectly reasonable question: is there a cut off point where the original defining characteristics of Prog are completely absent, yet we still recognise that modern artist as Prog?. Why do you object to that idea?

Post Progressive is a useless term invented by the press just to label modern prog rock bands that dont sound like Yes/Genesis/Pink Floyd and doesnt have any meaning to it whatsoever.

Oceansize, The Mars Volta, Radiohead and Anathema are prog rock bands without a doubt. In fact, TMV and Radiohead are two of the most experimental and progressive bands of the last 20 years. Muse and Elbow I wouldnt call progressive rock bands though they show very strong influences from prog. I havnt listened to the others.

I've not heard of "post-progressive" yet. 

I'we never seen the term before, the term itself seems fine if you talk about music in a historical way, it those new bands playing prog., without looking that much at how prog was played back then. But its hardly a genre.As if it was a genre you could say Fripp was post-prog, and thats not what you are saying is it. What you are saying is that it a period in music or ?.