A single console is one of those things that sounds great on paper, but considering how scummy the industry has been lately, would be used in the most anti-consumer way possible.
A single console on the market = Monopoly. Those are never good for consumers.
I wonder if something like the VHS standard could work in the modern day games industry. There's bugger all difference between the major game consoles outside of stuff that doesn't matter heaps, so perhaps some kind of open source gaming platform that can be manufactured by different companies that fits a baseline standard for performance and compatibility. OEMs building consoles that're compatible with each other but with different features to appeal to different folks. Gives other smaller companies a leg up in the console industry, letting them get the experience, equipment, and user base to become a bigger stronger player in the industry. Rather than racing to the bottom at the customer's expense, it'd encourage competition, companies trying to find their own niches and stuff.