There should be a wide variety of opinions on this question, and that seems to be true here. To me, "photogenic" isn't synonymous with "beautiful". There are people who definitely don't conform to a culture's norms of beauty who are easy to photograph so that a striking image - in one way or another - is more often the result. I think the comment above on "attitude" reflects this, and one important detail is the way the eyes and/or body language communicate emotion to the viewer.