They're never going to learn if no one ever says anything about a bad practice.
That's true, but people also don't learn from (and none of us enjoy) being attacked for what they've said. Constructive, positive explanations are of more value ("x has the following benefits because..." rather than "y is bad. full stop").
If that's the case then on this forum please ignore them rather than attacking them. We were all inexperienced once.