At many schools, advising is a professorial responsibility. Professors have a hard job, but they have a job that is very powerful and prestigious and can be incredibly lucrative (thanks to consulting gigs, patents, etc.).
The alternative, given the cost of housing near Stanford and faculty salaries, would be for faculty to live over an hour distant. The university acknowledges the benefit of having faculty live nearby, and also recovers the rent money and keeps the property.
2. It is usually the case that the university then owns a share of the equity in your house, and is owed a share of the profits when you sell.