I think Brexit has also been a significant factor in making UK way more xenophobic.
Personally, I don’t think it’s made the UK more xenophobic. A decent percentage of people supported Brexit due to xenophobia, and the success of the referendum made them more outspoken. Basically, Brexit is a symptom of xenophobia rather than the other way around.
The funniest part is that in one of his dialogue trees, he reveals that he’s never actually been to the Semenine islands and his whole understanding of Semenese culture is based on stuff he’s read and heard on the radio. He legitimately has no real understanding of the culture he presents as superior, and no place in it.