The point is Obama's order had a list of 7 countries training terrorists which Trump said he was using just like Obama. The difference was 1- that Obama used the list for vetting and checking where people travelled to see if they posed a terror risk; and 2- he did not have an automatice ban on everyibe from those 7 countries. This is important not just because it made Obama's method better, but because it made Obama's method avoid constitutional challenge and legal delay.