The past couple of years in US equities have been brutal for trending systems
Rather than brutal I would say less productive - the trend followers I know have positive returns for these years but not as good as years where there's been a long distinctive trend. I don't know anything about the specific folks you mention, but anyone with a 50% drawdown should not be in the business of giving advice. (Unless of course they have annual returns greater than 100%! :) )
I'm always surprised at how focussed folks are on return but not caring how they get there (drawdown).