That's true, but it's not really easy to apply.
Just one example:
I create Contest I, to participate you must use Form I which you can see in Notice I -> After participation you promotes to the group "Form Submitter" and Notice I doesn't appear again. Great.
But...
a week later I create Contest II... do I have to create a new "Form Submitter II" usergroup + New promotion + etc.?
I would be much easier to just click on the negative criteria option: "don't show this notice if form X was resonded".
Let me know if I'm wrong and it is easier to apply.
Anyway, that's only a improvement suggestion