This is the right approach. Good persuasion always starts with something the person really cares about, not something you feel like they should agree with.

Point 4 in @k00b's post is going to be more persuasive than the first 3 points even though there's less truth to it, because they all believe that's a huge problem.

I think another point along these lines would be to bring up undocumented workers. Talk about how Bitcoin makes it much more difficult to identify and deport them, as well as making it much easier for them to send remittances home.