Because there are people who live off rent (in a broad sense of this world), and there are people who live off selling their ability to work. Increased efficiency and productivity may or may not benefit the second kind of people, depending on whether they can sell their labour to be used for something else.

So instead of figuring out ways to limit the ability of people to live off rent, we want to ban beneficial things that people could extract rent from?

This is like saying, "We don't like how landlords extract value from housing, so we are banning apartment buildings"