What's problematic is that people don't seem to understand the travel ban. What I've described is is related to immigration control, and treating them like they're mutually exclusive will only allow the complacency of the past to creep back in. The fomentation of extremism in Islamic countries is a growing concern, more so since the emergence of IS. Supposing that those extremists decide to strike on American soil, and seeing as it's possible they can slip the net due to inadequate security measures through official routes, eliminating the possibility of them entering by that method automatically makes their job more difficult. Their ability to use unofficial routes is a another issue that doesn't make this any less true.
So it's an Islamic ban and the government has been lying from the beginning. If they think what you are saying, they should ban all countries with muslims, all countries with mosques.