Because sometimes the people lining up to get on tee vee are so low quality and un directable that it’s cheaper to slip someone who is directable a few bucks so you can wrap up your shooting and move on to editing.
Sure, sometimes. It’s just silly to say “all of them are fake”, when you know that most of the people they do use on the show really are people off the street.
So you have proof for your allegation that all the people trying to sell their stuff were actors?