The title of this article misrepresents what the article actually says. Despite the title, the article does not say that heart-rate zone training is a myth. Instead, it says that people are variable, and the "standard" formula of 220-age has variability, so that your actual maximum heart rate (HRmax) may be a little or a lot lower, or higher, than the prediction.
So I don't think he is saying that heart rate zone training is a myth, he is saying that you cannot be confident that the prediction of your HRmax will be accurate. He should be arguing that for people who want to train at 85% of their HRmax, it may make sense to consult an exercise physiologist to assess what their actual HRmax is, and to create heart rate zones that are tailored to them individually. For people getting started, another piece of advice would be to start at the 50-60% of predicted HRmax and work up gradually, letting your body's response to increasing exercise guide your progress.
But I agree that we should not blindly accept the HRmax prediction, and train at 85% of that number as if it were a gospel!
By the way, the formula
HRmax = 205.8 − (0.685 * age)
makes better predictions than the standard HRmax=220 - age
(for those statistically inclined, the standard deviation of predictions was measured at 6.4, so 95% of the population should have a true HRmax within 12.8 beats of the predicted value)