The answer to (1) is that you were warned for failure to heed moderator instructions.
The answer to (2) is that life is unfair. It’s probably the same reason that I got a speeding ticket when others who had been passing me, didn’t.
The answer to your unasked question: It’s only a warning. It’s not a whipping, or a fine, or being put in the public stocks. It’s the moderator saying, “Stop it!” in a voice intended to attract attention (as opposed to a mere mod note.) It’s a reminder to stop a behavior. In short: it’s NOT a big hairy deal.