Not to choose sides but... –
It is sad that they have to say something like this, but I have witnessed what they are trying to avoid,. They are there to sell product. I don't waste their time if .I am not interested in their product, but not everyone feels that way.
Sadly, a few haunters that go and snatch up expensive catalogs, and spend time chatting to the vendors with no intention of purchase, have ruined it for others.
I have even seen haunters talking in great detail about specifics of the props with the sole intention of trying to recreate it.
I can see why this would be off putting, but instead of blaming the show, maybe we should look at those who have pushed them to the point they have to make these statements?
Do Vegan Zombies eat heads of lettuce?