Swiveling legs give you the option to turn the legs one direction or the other to allow room for more pedals, typically a double base slave pedal.
All of the high end hardware makers have a swivel foot hi hat stand feature and many of them have a two leg option also.
I use a remote hi hat as well as skinslapper and a few others here. In my set up I use a rack system which allows me to have a
DW two leg swivel hi hat stand, a remote hi hat pedal and a double base slave pedal all right next to each other on the left foot.