While I was practicing drills tonight, it occurred to me that I have not seen roundhouse kicks in any form we do. All the forms I have seen in our system thus far, whether beginner forms or the more advanced ones, do not feature any roundhouse kicks at all. Though our style (a Northern Chinese praying mantis system that also descends from Northern Shaolin) features kicking that involves striking with the toe or instep, I can't ever recall seeing kicking movements that involve rotating the hip and body to strike.
When when I studied wushu from Bow Sim Mark (I can't remember exactly what style is was, but I do remember elements of Shaolin in it), I don't recall doing any type of roundhouse kick at all. Most of the kicks were, in general, straightforward in terms of delivery and execution.
Is the roundhouse kick common in traditional kung fu styles? If so, how widespread is it? What are the reasons why roundhouse kicks are not commonly performed if my assumption is actually true?