Quoted from ryanwanger:

Although I obviously would like all pins on location to be in pristine shape, I think the universally shared sentiment on Pinside that "this is what keeps people away from pinball" is flat out wrong. It may keep us pinball snobs away, but I doubt it's keeping away casual players and newbies.
There is a place near me. The hardcore pinball players all went once, and won't go back because there are issues with every game (not level, slings not working, weak vuks that take several tries, slow games), and the ambience is more like a YMCA than a place for pinball. And yet...the universal consensus from the non-hardcore is that it's really fun. These people don't know enough about pinball to know that the games aren't in top shape.
Now obviously, there is a range of conditions for games. The flippers need to work (unless it's an upper flipper, which many newbies wouldn't even notice) and be strong enough. The coin mechs can't be swallowing quarters. But beyond that - the only people who notice that the game is only playing 80% is us.
This isn't an excuse for poor playing pins in the wild, but by and large, it isn't causing newbies to turn away in disgust.
What percentage of the take is newbies and casual players vs. pinball snobs like us?