I used to print paper tickets so I could get into a show if my phone died / got broken / etc. That doesn't happen often, to be sure, but I also don't want phone bullshit to keep me out of a show that, in the case of this recent one, I have >$500 in tickets for. One less dependency is a good thing.
More to the point, the app isn't for my convenience. It doesn't do anything to make my experience better.