I'm a Brit, pushing 40. I'm educated to degree level (1st class, FWIW), and very well read (including the venerable Pratchett, though I don't think I have read Jingo yet).
I think I heard the word "jingoism" for the first time ever around 5 years ago. It is not a word one hears very often, and it certainly didn't come to mind from "JingOS".
If you often read high-brow political publications you may come across "jingoism" on the daily, but that is obviously not a huge cross-section of the public.
TBH, kind of bizarre how strongly this jingoism thing is being pushed in this thread.
I have used English as my daily working language in software development for over 20 years and had never heard it before.
Well, we don't discuss a lot of politics in international teams, that's a taboo topic especially when working with Chinese colleagues. And for Trump we have only one word, that I don't want to repeat here.