You're both right, its all a respect thing really.
I like to see Northern Irish players doing well for their clubs but if Northern Ireland had someone as good as Mahrez who played for, say, West Ham, I'd never be as disresepctful as to joining their club page and posting shite about joining a big team like Arsenal or Real.
Its about as bad as 16 year olds posting 'Messi still win man of match' about a match not involving Barcelona or Argentina in a pathetic attempt to be funny.