Osteen is such a charlatan that you don't need any spiritual discernment to see how thin and phony his gospel is. I think what Platt is saying is that many people in mainstream churches are believing a lesser form of the same $ gospel; we are willing to give God our eternal life while we pursue the bigger house, nicer car, etc. He points out the spiritual disparity between the picture you posted and the way many Christians live their lives against the way Jesus and the disciples lived and the Biblical call to service.
I think Platt is addressing churches like Lakewood. If everything is wonderful and God had a perfect plan for your life, why go and evangelize?