Why the bandwagon idea only works in advertising...

Why is it that when I bring up a problem or complain to someone of a higher authority, someone who could actually fix the problem, I am told that I'm not the only one who has brought this up? Why do people think this would make me feel better? If anything, it causes me to question whether I should trust them or believe they are in control of the situation. Maybe I should follow up that comment with a question like, "How many people have talked to you about this?" If the answer is more than ten, I should really worry. But, in my opinion, if it's more than one, then they're not doing their job, or they don't care, in either which case, there is something fishy that lurks there.