"Why?" Well, for once, this was kinda requested, if by requested you mean I took someone's indirect request, did it, then got a bit carried away and made a completely different mod separate from what they were looking for in the first place.
This mod allows for any sim to autonomously invite to move in with them. This means even your sim could autonomously ask another to move in with you. Of course if it is a homeless sim, this option I doubt will even appear so while testing make sure you know if the sims have a home or not.