To the average Mormon reader:
If a man came up to you and told you that he had visitors from Heaven that told him of a new church he needed to start, would you believe him?
Would you roll your eyes and give the man a look of pity because he is obviously missing from the psychiatric center?
Would you assume that the man claiming to be a prophet of God was honest and full of good intentions?
Would you not check the man out and see if there was anything shady in his past before you put your heart and soul into following him?
I certainly hope that most of the people out there would think twice about following a man like this.
Why then, should we assume Joseph Smith is everything the church portrays him to be? Why shouldn't we check things out (even things that are not "faith promoting")? Why shouldn't we ask questions and be vigilant about truth and honesty?
If you "know" Joseph Smith is was a prophet of God because you prayed and got a special feeling even though there is evidence to the contrary, why don't you take the time to pray about other people who claim to be prophets of God?
It is my belief that many people trust Joseph Smith because they were taught to trust Joseph Smith. They, like me, were taught stories about how good, honest, wholesome and honorable he was. They were only given half of the story, though.
It's the same reason so many people trust that Warren Jeffs is a prophet of God, or that other cult leaders are prophets.
How do you know that your special feeling is right and the other peoples' special feelings are wrong?