On the surface it sounds like a good argument, that married clergy can relate better to their married congregation, but than what about all the singles?
As a Biblical counselor we do not counsel from our experience but from the principles throughout the Bible.
Therefore, you don't have to be married to show what God says about the institute of marriage.
Also, married people sexually abuse children. Celibacy is not the problem.
IIRC, the stats tell us that the single largest class of child-abusers is "boyfriends."
Step-parents are not as dangerous as a class, and the cases of natural parent-abusers are almost nil.