Civil courts exist to provide monetary damages if damages can be proved to exist. Yes, they can also compel arbitrary behavior as a part of governing body.
This is independent of any stance on Zillow and a state licensing regime. If the plaintiff can convince that the tool is making her lose money, the judge will award her money.
"but that means < cue completely uninformed legal analogy >" yes you can make a career out of litigation, many people have.