Firstly, it should be known that calling ‘evil’ an ‘evil’ is not at all inappropriate. It is a norm across the world as well. If a person oppresses someone, then the oppressed one has all the right to call the oppressor an evil person. On the contrary, the oppressor has no right to feel hurt due to this.
When we express our Baraa’ah and curse enemies of Ahlul Bait (peace be upon them), we are actually calling out the evil of those people who oppressed the chosen ones of Allah, the High, and usurped their rights. This action of ours is, in fact, a Divine practice (Sunnah) as mentioned in the Holy Quran:
“Indeed those who hurt Allah and His Messenger, Allah curses them in this world and the hereafter and He has prepared for them a debasing chastisement.”
[Surah Ahzaab (33): Verse 57]
Hence, in reality, Tabarra and cursing (La’nah) is an expression of truth and should not be misinterpreted as hurting someone’s sentiments.