Wa aleikum salam
In my country it's also banned .. But i understand. If u are weari niqab, nobody can recognise u. So u can do whatever u want. Sister, not everyone is a good person or believes in Allah swt like it should be.
Some people will use it as a cover for bad things! I heard a story about a man who wore it to come close to women =S
I think people are scared if they don't know who they are talking to...
PLZ don't feel offended !