Worse, increasing the number of human settlements most likely increases the chance that someone, somewhere builds an unfriendly AI.
I don't see this logic. The chance of AI being made is based on how many people are working on it, not how many locations there are where people can work on AI.
I believe the reasoning is [more human settlements] --> [more total humans] --> [more humans to make an AI]. Whether or not settlements on eg Mars will actually lead to more total humans on the timescale we're talking about is up for debate.
Article on space.com