For a variety of reasons. If Sting reunites with The Police and goes on tour- sure, rent a football stadium. Some bands prefer smaller, more intimate venues. Some may have a hard time competing for the limited spaces at larger venues. Some may choose to avoid that level of fame. Who knows? It's none of my business.

Bands are always free to chase as much fame as they want, and to make their own policies about pricing or resale or whatever. I just think it's a little dystopian to say they're required to zealously follow some sort of capitalist ideal.

> Banning ticket resale is also expensive at scale.

Checking tickets at the door doesn't get much more expensive if you also require showing an ID with a name that matches the name on the ticket. You can even use the barcodes on most IDs, no fiddly reading required! Remember, you're trying to keep out the people who capitalize on scale, so if somebody sneaks in with a resold ticket and a corresponding fake ID, who cares? A 99% solution is fine.