"doesn't make the US any safer" may have a false sense of security - is an argument that looks good.  Except it is false.
Think. 
Why do people have a fire or Carbon Monoxide alarm in their house?  
Why do cars have seat belt?
Why do people get health insurance?
Life insurance?
And so on and so on.
The mere fact that the regions targeted by the EO is infested by Islamic Radicals makes it imperative that the US makes sure that not a single Islamic Radical gain entry into the US.
The report of the DHS is naive when confronted by the single fact of the existence Islamic Radicals infesting those regions.