People who do not react to gluten at all usually consume it socially or as a treat. I have never seen anyone here who was not celiac or seriously gluten intolerant say they go to the lengths that everyone who is celiac must if they are to avoid accidental glutening or cross-contamination.
But many who do react continue to consciously consume. The 80/20 concept is often expressed as a justification for eating up to 20% of your diet as gluten products, even if you react strongly. But not only that, it is expressed as justification for telling people who are reactors that they should be eating gluten, too. That they owe it to other people in social situations to eat something that may harm them long-term.
Now there's a belief for you, that even if you react to eating gluten, it is still harmless to eat and will have no long-term effects. It goes hand in hand with the idea that hardly anyone is really celiac, that most of them are avoiding gluten to annoy other people and feel special. Or that 100% of those who are celiac have been diagnosed by doctors, and there is no one who is celiac but doesn't know it.
Ah, yes, thanks to Zach's update, the belief that gluten intolerance is created by going gluten-free. Yep, I read that a lot from people who learned everything they know about gluten intolerance from their friends who are annoyed at people who don't eat pizza and burgers. Even the most incompetent doctor knows better than to think that celiiac is caused by eating a gluten-free diet.
But thanks to the fact that I learned what I know about gluten intolerance on celiac sites rather than here, these are ideas that I disregard in order to stay healthy, live long, and prosper.