Because of the obvious PR implications of having a program one's company wrote spewing controversial takes. That's what it boils down to - and it's entirely reasonable.
Personally, I wish these things could have a configurable censorship setting. Everyone has different things that get under their skin, after all (and this would satisfy both the pro-censor and pro-uncensored groups). It's a good argument for self hosting, too, because those can be filtered to your own sensitivities.
That would help with cases where the censorship is just dead wrong. A friend was working with one of the coding ones in VS Code, and expressed his frustration that as soon as the codebase included the standard acronym for "Highest Occupied Molecular Orbital" (HOMO) it just refused any further completion. We both guessed the censor was catching it as a false positive for the slur.