What I really wanted to say is hiring a wedding photographer is a lot like hiring a house painter. Lets say you have a outside wedding at a time of day that the natural light is good and the weather is not a problem. This is not unlike hiring someone to paint a wall with white paint. For the most part, just about any painter could handle it, even college kids would work. In this situation, you can probably get an amateur with a good photographic eye and get pictures you like. That is not to say that if you wanted a mural painted on the wall, the same college kids could paint a masterpiece and also if you want great photography, the best is still a pro, and the more expensive generally the better the work.
Now lets say the weather is terrible, the service is in a dark church, the reception is at night in a beautiful venue with a lot of reflective windows, and you have a million posed family and wedding party shots to do and only about an hour and a half scheduled. In this situation, the odds of getting great photography with an amateur, or even a starting pro, is about like hiring high-schoolers to paint the Metropolitan Opera House. Not a pretty sight.
And remember when the Pope wanted his ceiling painted, he went to Michelangelo, not Earl Shive (I can paint your car for $200).

Josey and Coleman at their reception in Youngstown
Michael Steinberg