Because they don't know you you're fresh meat. They know majority of tge freshmen guys because they went to jr. high togethet and the sophomores are the easiest to get than to go after Juniors or Seniors
Freshmen boys are immature. Very. And the sophomores are a step up. Also, many freshmen girls have basically grown up with the freshmen guys being in the same grade year after year. Sophomores are different.