One of the things which continues to throw a spanner in the works each time this subject is broached is the fact that people look at Bernoulli's theorem but only see the equation and forget to look at the complete definition, especially the limits to its applicability.
It applies to a steady flow of an incompressible, inviscid fluid.
If you have compressibility, if you have viscosity, if it's not steady - then Bernoulli does not apply, and will not yield 100% correct results. The error will depend on how much your application deviates from the defined required conditions.
Often, the errors can be ignored for all practical purposes. Outside of the boundary layer (but you have to agree on a definition of the boundary layer - leaving the search for the commonly accepted definition as an exercise for the interested reader) and at low airspeeds where compressibility isn't much of a factor, it'll generally be good enough.
That article seems to want to throw Bernoulli out the window as it doesn't apply in the parts of the flow where viscosity is significant. In my native language, we have a saying about kicking in open doors. That would apply, I think. Noone knowledgeable, especially not mr. Bernoulli himself, has ever claimed that Bernoulli's theorem is without limitations.