I'd be wary of overgeneralizing on that. I guess it depends on whose queries you're usually reading.

I think you're reading more into what was said than is really there

> I immediately become suspicious

All I read from that is, when DISTINCT is used, it's worth taking a look to make sure the person in question understands the data/query; and isn't just "fixing" a broken query with it. That doesn't mean it's wrong, but it's a "smell", a "flag" saying pay attention.