you need to protect something if it is under attack.
Zoroastrians practice their religion freely and since they are not a missionary religion (i.e. do not seek converts) they have no problem with the Muslim community.
They only part of their religion they can not practice is 'sky burial', which is prohibited by law on public health grounds.
a single case happened recently where the public elected a Zoroastrian to local office and the government canceled his election on the bases that he is not a Muslim, however that happens to Any person that does not follow the revolutionary-ideals of the Iranian revolution not only Zoroastrian.
Notice here, an Islamic majority elected a Zoroastrian, if they were second class citizen i do not think that would happen
However the public demanded his return and that what happened Iran Lifts Ban On Zoroastrian City Council Member -Radio Free Europe