I am highly skeptical that a significant number of 17- and 18-year-olds are so emotionally immature that being asked questions (very few questions, likely, since most people tend to mind their own business) they are under no obligation to answer will make it “the worst day of their school life.” Elementary or middle school, sure, but seniors in high school? In that case, they should not participate. If they are also so susceptible to peer pressure that they feel unable to attend school without participating, they should stay home that day. At that point, it’s less about the spirit day being problematic, and more about this individual being ill-equipped to function in normal society at a level expected of most people their age.