When you hear someone calling "CQ contest", but you don't know what the contest is, should you respond?
You want to help, but contest exchanges might need your class, contact number, etc, and you don't have one.
On the other hand, maybe contesters can easily say "since you aren't participating, I must be contact 001" or "since you aren't participating, you must be single-operator single-antenna class."
Is it annoying to explain this live on the air?