I would hate to think that we could be paving the way for countless errors just because img set is easier to implement in browsers. Implementation on the browser side takes place once; authoring will take place thousands of times.Mat Marquis in a special edition of A List Apart, discussing the two options emerging for responsive images and the recent collision between the WHATWG and the Responsive Images Community Group.
Tim Kadlec does a great job at breaking down the process which has led to the recent community disappointment in the WHATWG over the srcset attribute.
What message does it send when developers try to contribute their time, energy and effort to help solve a problem only to have it so casually dismissed?