In this video, Dr. Flowers claims that Calvinism is bad, because it might be discouraging to addicts and others who've suffered from rejection in life. I would contend that the opposite is true.
If you've been rejected your whole life, it should be refreshing to learn that God has unconditionally elected you, from before the world began, unto salvation, regardless of any merit on your part, not even the free-willed effort to believe or not believe.
It should be refreshing to learn that, as a member of God's elect, He will never give up on you, no matter how much you stumble in life, and will safely lead you to ultimate salvation.
In another video, Dr. Flowers says that if you are an addict, Calvinism doesn't give you any incentive to take personal responsibility over your addiction. The reality is that a good Calvinist struggling with addiction would ask for God's grace to help him, just as members of AA and NA do.
Also, even if we have no free will in matters of salvation, that doesn't mean we don't have any free will over our addictions. How many Calvinists refuse to do anything to improve their own lives, out of a belief that God is sovereign over everything they do?