Really? Both strollers and wheels on luggage are pretty nice to have even if you have to somehow negotiate curbs. So, I think it is a coincidence.
And people drag luggage around on city streets all the time. Many tourist destinations are pedestrian cities even outside their most central downtown areas. And luggage also needs to be dragged around hotels — and in suburban areas their absurdly large parking lots.
The skate wheels are a plausible argument, though.