Do I look like I have the plague?

As I rode on the train filled with handsome men in suits, I wondered if I had something on my face. When I got to the office, I hightailed to the bathroom to see if this was the case. Nope, nothing besides a little makeup.
           With all of my insecurities already blaring in my head, I'm curious as to a why a 22-year-old in business casual attire (black fitted skirt, pale pink turtleneck and a long string of pearls) would be left to sit alone?
            If anyone has taken a train on Metro-North, you'll know that the rows of seats closest to the exits can seat either four or five people, but facing each other. When I got on the train this morning, I sat down in the one with four seats. Another handsome man, but not my type, shared the small space with me.
           I took the seat closest to the window, so when he got off the train at the next stop, there were three open seats surrounding me. As males, young and old, filed onto the train, not one took a seat in one of the three remaining seats.
           They would eye the open seats, then their gaze would find me, which immediately caused them to look elsewhere for a seat. One guy, who looked as though he might be in high school, looked at the seat, then chose to stand instead of share the space with me. I know that this was not because I smell because I showered this morning.
           Calling all males out there reading this, could you please explain this to me? I'm baffled and curious about why no one chose to sit with me. Please be honest, or blunt, if that's what it will take to help me understand.