When I first began tinkering with using a single 45-pound plate in lieu of kettlebell swings, I soon realized that not only was this a movement that I could perform at nearly any facility due to easy accessibility, but that it also offered unique benefits.
First, driving a plate through your legs immediately forces the hips to open up and spread maximally in order to accommodate the wide implement. Second, plate swings greatly assist in eliminating one of the most common pitfalls associated with swings, which is squatting rather than hinging at the hips.
If you squat rather than hinge, you'll hit the ground because of the height of the plate. This teaches you to hinge and not let the weight pull you down. Instead, you'll learn to drive the weight back during the eccentric phase of the swing.