The tax has a benefit because we'll have better infrastructure to take care of things that make the city better. In this case helping homeless. I do want to help everyone, but for people that must have a personal improvement getting homeless people treatment and places to stay helps you because they aren't in the way. Having roads, cops, buses, and ambulances helps me too, but I also value those because I want to live in a better society that takes care of all its members.
Whether the tax has value to the employer is not well defined one way or the other. I suppose it comes down to the balance between utility derived and cost as with all economic issues.