Hatin' from the mid-west. Listen, I don't know about you, but I despise doing laundry. Their pricing is actually cheaper than the laundry mat down the street from me here in SF. It is a win! Plus, I get the tech; SMS when the driver is in route to pick-up and deliver. Time is critical for people working here, and shopping (InstaCart), chores (TaskRabbit/Exec), and now Laundry (Prim) are things I am willing to pay for.
It is true developers/entrepreneurs might have more disposable income here in SF than other cities, but we also have a startup for anything you need. I like the ability to pick and choose what I am willing to pay somebody else to do. Startups should make people's life less shity; I'd say Prim accomplishes that.