I lived through the whole saga, and I never thought "JRPG" was a slur until a Japanese developer said it a few years ago.

My theory is that they get a lot of hate directed right at them because they're the developer, and don't realize that it isn't a slur to most people. There's no label out there that isn't used as a slur by someone, especially while spewing their particular brand of hate.

IMO, Japanese developers should get over this label and just keep making good games. Ignore the idiots. You're never going to turn them into customers.