(what is up with this pattern in the exercise world?)

I don't particularly know about exercise, but once, being annoyed by all of the spammy advertisements that say "Never do this exercise!", I googled for that phrase. It seems that everyone with an exercise blog has some set of exercises to "never do". I suspect it's simply a clickbait pattern, the same as for those ads: choose something unremarkable and be conspicuously against it. Being right is optional.