> What more does supporting it entail than being sympathetic to the sentiment?
It is a bad, counterproductive impulse that will hurt their society long term, just as I think xenophobia in the US has been counterproductive.
You should also recognize that there’s a difference between the people who visit, and the people who completely restructure their lives to immigrate. And there’s a difference between immigrants who do their best to learn and integrate into the culture, and immigrants who try to impose their culture on the host nation.
Xenophobia doesn’t really jive with recognizing people as individuals and recognizing that a foreigner can learn Japanese well and follow the cultural norms (aside from the norm of having been born in Japan to Japanese parents, but only because it is impossible for a gaijin to do that).
In other words, I don’t think it’s right to broadly group immigrants into the same bucket as disrespectful tourists, but I also see on a human level how that impulse arises. The greater majority of well-behaved tourists don’t stand out like the problem-causers do.
> Are the Japanese really terrified of foreigners or just annoyed at misbehavior
The “phobia” part of the word is probably confusing you, in actual usage, xenophobia encompasses dislike, “fear” is not necessary. Similar to homophobia or Islamophobia, the term includes fear _or_ dislike/hatred.