We are not talking about people called Rose – or Rosenberg or Rosenblum or anything similar. The reference is to the Chanukah song, Ma’oz Tzur. It has a verse which says, “They breached the walls of my towers (i.e. the towers of Jerusalem and the Temple) and defiled all the oils – but from the remnant of the flasks a miracle was wrought for the Roses”.
The word shoshanim – roses (though another translation is “lilies”) – was probably introduced by the poet because he needed a word that rhymed with kankanim, flasks. Nonetheless, there are other places where the Jewish people are likened to roses. Think of the Purim song Shoshanat Yaakov, “The Rose (or Lily) of Jacob”. This might also have had a prosaic origin in that the story is about the Jews of Shushan and the word Shushan yields the play on words with which the song begins.
Midrashic sources – especially the Midrash on Shir HaShirim – say that the righteous are compared to shoshanim, and if the word is understood as roses the idea could be that the righteous are handsome in their deeds but prickly if anyone tries to exploit them.