LANDLORDS IN SEATTLE NO LONGER HAVE A CHOICE WHEN RENTING THEIR PROPERTIES

Have you heard the advertisement for the AC and plumbing contractor who says he makes sure the people he hires are friendly by testing how his dog reacts to them?  When I heard that I said to myself, there’s a discrimination claim waiting to happen.  
I was reminded of that today when I read a post on Overlawyered about a new law in Seattle that requires residential landlords to rent to the first applicant who meets the landlord’s pre-published criteria.  In other words, no fair choosing one prospective tenant over another based on the landlord’s subjective judgment.  Of course basing that choice on the applicant’s race, national origin, gender, or marital or family status is already prohibited, but this law takes it one step further.  Can the landlord choose one applicant over another just because one applicant is obnoxious?  Not under this law (well, you could include “no obnoxious people” in your criteria, but that’s too subjective to be enforceable).  
So how long will it be before the AC and plumbing contractor is accused of discrimination, or has his discretion in choosing his employees taken away by a law similar to the one for landlords in Seattle?