Banning something because you do not like it, but does no harm, is just as oppressive as obligating someone to wear what you want.
If these people that do not like the burka, etc, are perfectly content in the presence of nuns, then their "discomfort" must be pure prejudice.
Apart from that, the real reason for the garment is probably lost in the mists of time. Just like circumcision, not eating pork, or bleeding of animals in slaughter, etc.
These practices probably served a useful purpose at one time, and were written into certain "scriptures" to justify and oblige the believers into adopting that practice.
The burka, or whatever could be construed as a sensible garment for protection against the sun. The writers of the "scriptures" adopted an already well-practiced habit (pun intended) to serve their own religious ends.
But if we ban one visible 'religious' requirement, we must surely ban all visible religious requirements.
Therefore nuns would be required to not wear the uniform, in case they cause someone discomfort.
