Well most incarnation of the Flash, comics, cartoons or TV shows, generate some lightning, but it's a DCEU thing, to my knowledge, to have said lightning be especially potent, and act like some sort of tesla coil, and is even blue, like real electricity arcs, instead of the typical yellow.
Hence the tethers. I personally like it, how the speedforce is a living, powerful thing that actually interacts with Barry and its surrounding, but once again it's a choice by Snyder and co that might not please everyone.
Although, frankly, I think it's kinda of a useless thing to nitpick, especially given WB's track records. We would be very lucky if that is the only problem of both JL and the Flash movie !