I already responded to this point at length here https://news.ycombinator.com/item?id=49892375 but in brief: on this interpretation, mobile phones should actually result in more successful drop-bys, because you can call or text when you're "in the neighborhood". Thus, mobile phones are not an excuse to avoid home visits.

You're still missing the point entirely: A lot of those visits are not wanted and weren't wanted to the point that unwanted visits were a trope in media.

Before they would happen because we had no ways to stop them until someone was at the door with a plausible excuse.