Not all of us have cell plans with hotspots ($$$), hotspots often have data caps, cell is often slower or congested, and there are some areas without cell signal. It's also kind of silly from a wider perspective to shove everyone onto the cellular network when most businesses have perfectly decent fiber internet nowadays.
Sure, I'm usually on hotspot, but I personally appreciate when businesses have wifi. Either way, there are always going to be shared networks somewhere.
I'm not sure how you're getting that from their post? None of the four things mentioned (book publishing, web publishing, open-source software, computer hardware) involve stealing someone's property, he's saying that the ability to produce those things widened and the cost went down massively, so more people were able to gain access to them. Nobody stole your bike, but the bike patents expired and a bunch of bike factories popped up, so now everyone can get a cheap bike.