Might have been Automobile Magazine that pointed out that buying an ELR was like buying two Chevy Volts and getting only one, and nobody wants to buy a Volt.
Not anywhere near the same segment as the Tesla Roadster, so it's not really an apt comparison. The reason it didn't sell is because they were trying to make a luxury car based on fuel economy. That's a hard marketing job (because people who buy luxury cars don't give a fuck about fuel economy), and a niche that apparently doesn't need to be filled.
The Model S is a performance level toy. GM made the same mistake that you're making by comparing the two. Namely, thinking that rich people wanted an eco model. So, they made a really high end hybrid, because they know how to make hybrids. But if rich people wanted that then Lexus would have beat them to it like ten years ago. Lexus didn't do that, because they apparently are smart enough to understand that Tesla's success is in trading on the faux-eco brand with Mac-like coolness, while still offering a fuckload of horsepower and torque. They're not similar.