I'll tell you what's challenging: photo lamps. Why did they diverge so greatly from theatrical lighting? Why can't I focus a strobe like a 6x9 elipsoidal? Why can't I slap a filter frame or barn doors on a strobe like a fresnel? What about gobos?

Ever try to use a color gel with an umbrella? Those dish attachments always get in the way. Somebody's got to give birth to a new design standard! How about a lense instead of a dish? Still photogs like spots and colors too. And make the attachements interchangeable, while your at it.