It's hunting season. Maybe they have been hunting, are going hunting, hunting clothes are in the rotation, or just like wearing camo during the hunting season.
I often wear a camoflauge shirt to Walgreens or Lowes during the winter. I don't wear the trousers because it looks silly, and I don't want to get the scent on my hunting clothes. But maybe they are small game hunters.
Did their choice of apparel do you any harm?