The ability of some traders to make consistent significant profits should be an "existence proof" of the inefficiency of markets. The EMH is just wrong.
The question is not 'can traders make a consistent profit' but rather 'can anyone make a profit using just publicly accessible historical data alone' this is the essence of EMH.
Most professional money managers make their gains by actively interviewing companies in a form a stylized intentional financial journalism if you will.
And not just "some" but a proportion of profitable traders greater than what we would expect due to chance - i.e. the existence of some lottery winners does not prove that playing the lottery is in general profitable.
Most professional money managers make their gains by actively interviewing companies in a form a stylized intentional financial journalism if you will.