Have you ever visited someone who lives in an apartment and not had a phone on you? Do this often enough and you've quickly get sick of buzzer systems that have evidently been broken for months or years, intercoms that require you to punch in a code that the person you're visiting didn't think to give you (and may not even know), and, in some cases, buildings that lack per-apartment doorbells entirely.

If ever any brain needed to be put in a robot body, it would be that one.