Wow, that's a really interesting point you bring up. It's really made me think. When I saw that bit of the preview, I cringed just thinking about how torturous that exercise always was in elementary school. You are right: As an adult, Sean doesn't have to subject himself to such a humiliation. In order to be true to himself, Sean should take the dignified route by passing on the activity. But I can also understand the pressure that must be involved in that scenario. If the only way for the guys to get one-on-one dates is to win some stupid athletic contest, then I imagine it's hard to take the high road knowing you might miss out on an opportunity. The guyathalon proved that coming in last place is okay, as long as you don't give up. Maybe Sean was hoping he'd win a date based on that logic - twice. The more time you get to spend with the girl, the better chance of winning.
I would love to see a reality show contestant take the high road. Then again, that would be somewhat antithetical to the premise.