Trek from the very beginning has offered powerful commentary about prejudice and the fear, anger, and hate associated with it. And the recent episode was very much in keeping with the Trek tradition of commentary on these issues.
But what occurred to me after watching this episode was an important truth about fear, anger, and hate and how both Una and Spock are victims of prejudice because of these attitudes.
The Earth suffered a devastating war because of tyrants who were created via genetic engineering. Vulcan civilization was almost destroyed because of wars and conflicts due to passionate emotions. As a result, Earth (and later the Federation) banned genetic engineering of people. And on Vulcan, there is a strong cultural taboo against emotion. (BTW, the case could be made that the puritanical prohibition against emotion in Vulcan society is both illogical and driven by fear but that's a whole other story.)
Having fear, anger, and hate of something which is abstract is difficult. Having fear, anger, and hate against people is far too easy. Una testified on how Illyrians were subjected to prejudice and threats of violence when she was young. It's because the Illyrians were the easy personification of something citizens of the Federation were taught to fear and hate.
Spock, being part human, is the personification of the Vulcan fear of emotion. And he was subject to bullying and prejudice throughout his youth. Growing up facing prejudice in such a rigidly puritanical society is why Spock spent so much of his life having difficulty about his identity and how he should handle emotions.
In our current times, blue collar jobs have been disappearing from industrialized countries due largely to automation. This fear of job loss was featured in the TOS epsiode The Ultimate Computer. But directing fear, anger, and hate against something abstract is not easy. By the 80s, media figures, pundits, and politicians were personifying the fear of job loss via Asians. The anti-trade rhetoric at that time contributed to the murder of Vincent Chin (whose killers were prosecuted but never punished). And plenty of media figures, pundits, and politicians across the political spectrum have been pushing anti-trade rhetoric since 2008 even though I'm certain a good number of them know this inspires racism against Asian Americans and immigrants. (There's a good reason why anti-trade beliefs have been embraced historically by racist and nationalist ass hats.)
And in recent years, vile and opportunistic media figures, pundits, and politicians have sought to personify people's fear of social change via the LGBTQ community.
Don't fall for these things. Don't be similar to the humans or Vulcans who directed prejudice at Una and Spock because they were the personifications of what those people feared.