Good point on the perspective of where my responsibility ends. I do desire to see people make use of the services they pay for. But you make a very good point!

Does an exercise equipment company lose sleep when hundreds of customers buy their treadmills and elipticals, only to let them sit in their closet gathering dust? Probably not. They, like you, run a business. Your responsibility ends once you've delivered the product/service. So you shouldn't feel bad that he hasn't done anything with all the help you've given him. I can understand why you'd be a little disappointed though. And yeah, his e-mail response was completely out of line.