Interesting. I think equating "suicide" to "kill" is not correct, however. If the "kill" command were actually called "murder", then the analogy (used by those defending the term) would be more complete.
In short: I agree that "suicide" is markedly more upsetting to some than "kill", and probably should be changed.
In this case, the denotation of suicide as the voluntary choice to end oneself is certainly more valid than kill, as the tests in the related PR indicate (https://github.com/cjihrig/node-1/blob/c0de81bd09875c8ff9b3f...). This conversation feels to some extent like political correctness, which I'm generally opposed to–words are just words, and we have to call things something–though the use of the term "suicide" when "detach[ed]" would have sufficed, was rather rash.