That's right. And it is an issue no doubt. It poses a trade-off situation: do I give up a little overall sharpness to gain the wide dof, or do I max out the performance of my gear, but give up holding a whole frame in acceptable focus? It's a creative decision that people who know what they're doing make. And sometimes the decision is made to permit diffraction because other goals are more important. It's a serious concern and I like to shoot landscapes about f/11 mostly. That there is a perfomance hit at f/22 is undeniable, but the notion that no one who knows what they're doing would never use f/22 is deniable and very objectionable.
I agree. It's not denying it's existence it's understanding how to work with it. Bryan Peterson is another pro that is constantly at higher apertures, even in his videos.