Well, it quite well known that gluten creates several problems for SOME people. That's quite a different argument from the over generalization you did at the GP.
It's indeed something to keep in mind, but the good news is that it's easy to test for.
Gluten intolerance isn't a binary state, it's a scale. Everyone's on it somewhere, but unless it's REALLY bad, you'd probably never get diagnosed or even tested.
Main benefit of avoiding gluten though is it's a simple rule that helps you avoid a lot of bad foods, and excuse it socially.
It's indeed something to keep in mind, but the good news is that it's easy to test for.