Yeah, so I ride a triple because I'm slow, fat and weak.
But here's a story. Riding one day with a buddy, and a female rider pulls up behind us. She starts chatting it up about her race the next day and asks if she can tag along. She asks what our intended route is and if we plan any big hills, because she doesn't want to overexert the day before a race. We tell her we'll take some moderate hills. It soon becomes obvious she's using us to draft so she can save energy. That's cool, whatever. Soon we come to one hill that we consider moderate and she starts protesting about our choice. She's got to stand on her double setup while my friend and I spin, easily keeping pace. After the ride, she admits she dislikes hills, and opines that most racers do. That's why there are virtually no races in our region (there was one last year, but apparently it was deemed too hilly by most of the participants). Most of the races she participates in are in Pennsylvania and south.
Don't get me wrong. I know many road racers train on hills, and this particular woman's preference to avoid them is a personal choice. However, I believe she said she is Cat 2...and she has been Cat 1 in the past, so she's not exactly a slouch. But I do notice on most of my rides that there are a scarcity of riders on some of the more difficult hills. They stick to the faster, better paved, less hilly roads. I do see them descending some of the hills sometimes, but rarely if ever climbing.
Now, is this a function of the equipment defining the nature of racing? Or are most riders who like racing less inclined to punish themselves on hills? Or both? Or could it be that my observations are purely anecdotal in a region where competitive cycling isn't very big?
I will add that while racers in the TdF don't ride triples, many participants in the PBP do, where it's acceptable. In this case, I do wonder if the equipment shapes the nature of each event.