That would require calibration (this is the layout of the store, the receiver is here, reflections can occur here and so on) while a GPS system would allow owners to just connect to a centralized app and bam, here is where all your visitors walked for the last 3 months.

wow, that's your retort/sales pitch for GPS only tracking? it truly needs some work.

Nope, it's simply information, free for everyone to read :) I'm neither selling or arguing for/against anything.