Was I in the wrong?

[Eloah]

Sometimes life includes things you don't want to hear.
Someone may be playing very incorrectly, to the point they are unknowingly causing disruptions in the party.
You want an ice mage to never be told using fire spells is how the job works, simply because he may be offended over being told he's playing wrong? Want someone that doesn't know the difference between stack markers and proximity damage markers to never learn?

These are simple examples, of course. Lifes intricacies means much more subjective themes. You'll never be able to please everyone, so the best course of action would be open discussion. Not just blanket claiming everything can be considered harassment.

I don't think you got what I meant. There is a difference between saying something someone doesn't wanna hear and harassing that person. In your ice mage example, if you try to tell them that they are doing something wrong by informing them about the proper way, that is not harassment, because it's not something directed at them it's directed to them; similar to the laughing with you or laughing at you thing. But if you were to poke fun at the way they play and how stupid they are for not using this spell or this rotation, then that would be harassment.

Plus, if the person on the receiving end says stop and you or anyone persist, then it's definitely harassment at that point.