How can a word be a bomb?

And I'm still at a loss how in a supposedly post-enlightenment world, a single word can be so evil that you have to resort to code to refer to it, no matter in which context or whether or not you're quoting.

Yes, you shouldn't call people that way - and if you do, that is a clear sign of a racist mindset. But treating the word itself as some kind of forbidden symbol that must be purged from everything is not much better than medieval magical thinking.