Because they have at least Price, Horsepower, Horsepower RPM, Torque, Top Speed higher than the average of all motorcycles of their category:

SPORTSMAN ACE 570 ATV, horsepower (45,62 ps),
SPORTSMAN XP 1000 TOURING EPS ATV, horsepower (89,22 ps),
SPORTSMAN XP 1000 EPS ATV, horsepower (89,22 ps),
SCRAMBLER 850 XP EPS ATV, price (17.899 €), horsepower (78,07 ps),
SCRAMBLER XP 1000 EPS ATV, horsepower (90,23 ps), horsepower rpm (7.250 RPM), torque (93,50 Nm),
SPORTSMAN 570 FOREST ATV, horsepower (44,61 ps),
SPORTSMAN 570 TOURING ATV, horsepower (44,61 ps),
SPORTSMAN 800 FOREST ATV, price (11.620 €), horsepower (54,75 ps),
SPORTSMAN 850 XP FOREST ATV, price (14.426 €), horsepower (78,07 ps),
SPORTSMAN 850 XP TOURING ATV, horsepower (78,07 ps),
RZR 4 800 EPS BUGGY, price (28.167 €),
RZR 570 BUGGY, price (17.493 €),
RZR XP 900 BUGGY, price (27.639 €), horsepower (76,04 ps),
RZR 4 1000 EPS BUGGY, horsepower (108,48 ps), horsepower rpm (8.500 RPM), torque (94,90 Nm),
RZR S 800 EPS BUGGY, price (21.033 €),
RZR S 900 EPS BUGGY, horsepower (76,04 ps),
RZR XP 1000 EPS BUGGY, horsepower (108,48 ps), horsepower rpm (8.500 RPM), torque (94,90 Nm),
RANGER 570 EFI UTV, price (17.493 €), horsepower (44,61 ps),
RANGER 570 EFI CREW UTV, horsepower (40,55 ps),
RANGER XP 900 UTV, price (27.639 €), horsepower (68,94 ps),
RANGER XP 900 CREW UTV, horsepower (68,94 ps).