The "shoes inside" thing always becomes a heated discussion on reddit, and my guess is someone from Arizona or Florida is arguing with someone from Boston or Minnesota about wearing shoes in the house.

I think this is a regional thing. In the north/northeast, "outside" is filthy for a good part of the year because of the salt, sand, gravel, snow, muck, slush, and all kinds of other shit that accumulate over the winter. So between November and April, it's often heavy boots, with big treads that capture all kinds of shit in them. Nobody is going to enter a home and walk around with obviously wet, dirty boots.

In the spring/summer months after a few big rain storms to literally wash all the gunk away, it's more common to see people wearing their summer footwear around the house.

What I find weird though, regardless of the time of year, is when people shut it down for the night and hit the couch to watch a game or their favourite show, that they still keep their shoes on, and put their feet up on an ottoman or coffee table while still wearing their shoes.