Because the Mexican flag is not being flown over any state capitol or federal building that I know of. The Confederate flag is. And people are talking about taking the Confederate flag down from government buildings, not banning the ownership of it entirely. And honestly even if it were flying over government buildings, I'd consider a drive to remove the Mexican flag as stupid and as pointless as the drive to remove the Confederate flag is.
They aren’t just talking about flags flown over state capitols - they are talking about wanting to having it removed wherever they can.
Why do some people get to decide what symbolizes ‘hate, racism, and bigotry’ And decide what others may do with their freedom?
Where is the Battle flag being flown over a government building?
That would be really different in my book.