I too wonder if this is a UK/US thing. I've never known anyone to take particular offense to the word 'rube' (in the US). Well ... at least not in any sense relating to xenophobia. And Lugia didn't even use it as an insult ... he used it to mean someone not educated or cultured enough to see through the marketing buzz and snakeoil. Which is what the word means. What would be a better word to use in this context?