I have to disagree to some extent with the idea that Michael brought this on himself.
My thoughts are a bit disjointed but bear with me!
Michael's clear and emphatic statement that he would still have children in his bedroom meant only that it made the second accusation easier for the public to believe.
The Arvizos would have accused Michael of molestation one way or the other! Once they failed to get what they wanted from him, they knew that was their best weapon.
So it was immaterial if Michael had children around him or not. He could have proclaimed that he was done with children. The Arvizos would have accused him and people would have thought he had just gone into hiding with his nasty little habit.
But Michael remained true to himself. He also put safeguards in place - permission from parents, the presence of another adult at all times, etc.
Michael's statements did not make the accusation any easier to make (the first accusation did that). All Michael's statements did was to make it easier for people to presume his guilt, because of his perceived access to children.