^^ interesting, highly opinionated link. not true for me, but if it works for that guy... great!
drop bars, for me, lack the leverage to steer and maneuver a MTB efficiently. I have seen guys ride CX bikes with drop bars on singletrack. I have never seen a MTB with drop bars other than that link above.
I love drop bars on my road and CX bikes because I don't need a ton of steering inputs and I use the drops to get lower and more aerodynamic, which matters a lot at 20mph on the road and very little at 10mph in the woods.