That's an old article, and Musk has since updated his estimates and dates, and was explicit that they would target burst builds before ramping full-time [1]. But that's beside the point - the question is, what is the source of skepticism of the ability to execute at all (not by a particular target date)? We can go back and forth on dates and numbers all day, but that's not my question.

[1] https://bgr.com/2018/04/17/elon-musk-model-3-production-6000...