Because as you know, non-citizens can get REAL IDs, and Trump signed legislation that allowed for certain non-citizens to have permanent REAL IDs.
Anything that is either only given to citizens, or has some obvious "Person [X] is / [ ] is not a US Citizen" indicator on it.
I'd assume that the relative lack of a suitable ID card (in the US) was the point that user RicoElectrico was trying to make.