It matters that muslims wear islamic clothes - hijabs and burkhas for women, skull caps, robes and beards for men.
Firstly, wearing this attire is a political statement, an act of defiance - we will not fit in, we will live our way in your country. And we will make your country ours. Dressing this way is part of creating a Middle eastern Islamic world in Australia (and every where else). Colonisation, in other words.
Part of this colonisation is the building of mosques and schools. Whenever a mosque or school is built, a bit of Australia dies and is replaced by a bit of the Middle East.