I dont disagree with anything you just said, but i was only talking about Quad Module or 5x Module SteamRoller and Excavator SKUs at 20nm that were canceled due to GloFo pursuing the process they needed to compete against TSMC and the others.
It was that moment that both SteamRoller and Excavator Server parts were doomed and AMD had no choice but to change the entire roadmap up to 2016 for their entire portfolio.
It wasn't a decision made in a vacuum to AMD's interests though.
It was a business decision reached by both parties once GloFo had enough data to determine how much it would cost to develop the process tech that AMD wanted, and AMD told GloFo they were not interested in paying for it if it was going to cost that much.
Ultimately it was AMD who made the business decision to cancel their own SKUs and for GloFo to cancel the development of the high performance 20nm process.
No different than what happened to 45nm and 32nm at TSMC (the customers told TSMC not to spend R&D money developing those nodes, not the other way around).
In process tech, IDM and foundries alike, it is not a "build it and they will come" business. You only start building it (start developing the node) if at the same time you have customers who are willing to sign contracts (4 yrs out) or letters of intent to have their chips fabbed on that node.
If there isn't enough seed-interest at time T-4yrs, then come time T the node will have never been funded for development in the first place. But it is the customers who ultimately direct the foundries in terms of what to build, when to build it, and how fancy (expensive, performance, etc) to make the node.
It really isn't correct to lay blame of AMD's product SKU situation at the feet of their foundry when it was AMD themselves who made the business decision to direct GloFo to go cheap on its 20nm process flow, knowing well in advance that such a decision had the unavoidable consequence of undermining the viability and competitiveness of AMD's planned CPU designs.