Because for most of the cases people really care about, it's easier for you to change your language then it is for every offended person to not feel upset when you offend them.

This might not be the case if there's a downside to the alternative language, or if the feeling of offense is unreasonable, but this is a decision you should actively make, not passively dismiss as "not my problem".

In this case, I think the language could easily have been changed without significantly weakening the text.