Part of being able to make an informed decision is hearing the opinions of others. This is the essence of free speech. By allowing ourselves to engage in open and friendly discourse about a number of things (religion, politics, WDW vacation strategies) we hope to arrive at a decision which is the best possible option for those participating. If you do not want to be "impressed", you won't be. If you're not interested, it's perfectly acceptable to say "No thanks." However, there are people out there who are interested in shopping for a religion, just as others are interested in shopping for a political candidate to back. They're undecided, and some friendly talk might help steer them to their correct decision.
Jehovah's Witnesses have been at the heart of some of our country's greatest legal battles. Although their presence on our doorsteps may not always be appreciated, all American's owe them a debt of gratitute for sticking to their beliefs and helping to provide us with the broad speech rights we have today.
Off soap box now.
What you should be asking is, "Is it right for parents to force their chosen religion upon their children, without giving them any exposure to alternatives?" I was raised in something of a religious vacuum, and I feel it is one of the things my parents did really right.