I'm a lifetime, dyed-in-the-wool atheist myself, but I don't know that I agree with this assessment. While it's not hard to find those who exploit religion for personal gain (money and/or power), the good majority of clergy are simply ideologues who are looking to spread their beliefs and morality. Most clergy have maybe a few dozen or a hundred or so followers, and know they'll never be millionaire televangelists.
Religion continues to serve important emotional, metaphysical and communal needs for believers. Ultimately, people believe because they want to believe. Religion gives people comfort and strengthens social & community ties. It gives people hope and purpose, albeit false.
While there is much to dislike about religion, portraying it as merely a system of social control is, I think, a gross oversimplification that leaves out many of its other uses and effects.