The overwhelming majority of lights are within human reach with no protective casing. There might be a lampshade to diffuse the light, and some frame to physically support the bulb, but nothing to stop a human hand from reaching in and touching it. Hell installing and replacing bulbs is typically done with bare hands. Free hanging bulb lights used to be quite common in closets and basements.
I guess i assume the point here is to have no protective case since the article made such a big deal about touching the display.