Is it? In the US, I'm not aware of any way someone can legally drive, be employed, have a bank account, or get a cell phone without having an ID. At the same time, as long as you were registered at birth, getting an ID from scratch is a little bit of legwork and probably less than $100, and that's probably subsidized if you don't have income. The number of people walking around without an ID and no way to get one has to be vanishingly small. I'm sure there's a certain fringe of people who are undocumented, on the run from the law, or otherwise encumbered in their ability to get one, but how far should we bend over to get a ticket fee from those people?

Edit: Dang it, the best answers always come after I close my laptop. "It would be discriminatory if the government didn't provide people a way to get ID. As a business owner, that's beyond the scope of my responsibility. Same as if someone showed up without $5 and wanted to buy a sandwich." ...is another way to look at it.

Who knows, if voting doesn’t motivate them, but concerts do, maybe it will cause more people to get IDs. Isn’t that a good thing?