This should make the people shut up who claim ZUN is a racist/western hater/xenophobic person.
Indeed, while he has expressed most of these points before, this interview actually has ZUN laying out his entire logic in one place.
The crucial thing is to understand that ZUN, true to the doujin spirit, sees his doujin publications (the STG games) as entirely his own baby, created, and in an ideal world, put into the players' palms by his own hands. From that perspective, letting anyone else tinker with them, be it hired programmers or fan patchers, can feel like an invasion of privacy.
A corollary is that if the games need to be changed in any way, whether for patching or international localization, he would have to also handle it by himself. And this creates a deadlock, as he often has neither the motivation ("I want to make new things, not fix old ones!") nor the capabilities (new programming techniques or foreign language skills) for the tasks.
Or in other words, he's not a xenophobe, because he hates and distrusts all people equally
.