So, by your logic... If no one ever got divorced and no one was ever unfaithful, you would completely understand why gay people can't marry? It would make more sense to you, and you could comprehend how it might destroy the institution, if that were the case? Is that what you are saying?
We could apply your same logic to driver's licenses. People drive recklessly all the time, causing accidents, even killing people with their careless driving... so why not do away with driver's exams, and just allow anyone who is old enough to reach the pedal do it?
Got another one... this whole 'democracy' thing has become so nasty and partisan, why don't we just allow the strongest man to fight his way to the White House, and rule as our King instead? If someone doesn't like what he is doing, they could go challenge him to a fight, and if they beat him, they would take over the throne. I mean, the 'institution' has already been corrupted, politicians taking bribes, not representing their constituents, what difference would it make if we just changed the rules? May as well give that a shot, couldn't be much worse, right?