I think you are incorrectly guessing the content of the article based on the title.

The article doesn't say that more people refused than was previously known.

It just concludes that most people weren't following instructions in a way that would have supported the validity of the supposed memory experiment.

Indeed. Just knowing that the subjects who followed through with the shocks were less likely to obey the rules could be interpreted in many ways, some invalidating the results of the experiment, some just suggesting a mechanistic explanation, and some making the results even more concerning.

* Did the subjects who went full voltage stop caring about the "learning" protocol because they realised it was all fake? Then the conclusions of Milgram's experiment are invalid.

* Did the subjects who went full voltage make more mistakes because they were more anxious and fearful of the experimenter? Then underlying fear might be a mechanism for blind obedience, and further research would be interesting.

* Did the subjects who went full voltage just enjoy electrocuting the dude so much that they stopped caring about asking the questions correctly? Then blind obedience is the least of our worries, widespread sadism is much more concerning.

It says more then that. The "psychopats" were NOT following the rules. The rule followers were not cruel.

The act of torturing was not due to the torturer obeying the rules. Instead, torturers broke the rules and created conditions that allowed them more torture.