My favorite example of gear-itis is Nikon's list of Magic Lenses that are recommended for the D800 wundercamera.
Their current bottom of the line camera, the D3200, has a finer pixel pitch, and is therefore more demanding of lens sharpness, then the D800 (yes yes, only in the center, etc etc) and yet we see no magic list of lenses for the D3200. They ship it with a very cheap kit zoom, which is evidently good enough.
And yet, having paid an immense sum for a D800, many will rush out to replace their current lenses with Approved and Recommended lenses, and (more obnoxiously) will bore other people to death with discussions of how the old glass was just Totally Inadequate on the new camera, which is simple Much More Demanding.