They're getting popular. I don't get it, but I do recall being a teenager 40 years ago, and sliding around frozen parking lots with my VW bug. The younger guys get it. Safer than doing it in a car. Although using PVC to lose traction seems whimpy. Slap on a monster two stroke with hard slicks, and I'm there.
Come to think of it, there are several vintage karts out there racing right now, which incorporate a rear wheel traction loss in turns to set their angles up.