Seriously? You're gonna make a verbal complaint about that? Let's recap. You entered and used a public bathroom. I repeat, a public bathroom. Some public bathrooms can be found in a less-than-appealing state, but this bathroom, at this time, was clean. The toilet was clean. The floor was clean. The walls were clean. Everything was clean. I presume you did your business then went to wash your hands. There was a bit of water on the counter around the sink. You then exit the bathroom and take the time to go out of your way to find a staff member to whom you remark, and I quote exactly, "the bathroom could use some attention". It's a public bathroom for crying out loud! You're a big boy - I think you can put up with a bit of water on the counter without making a fuss about it.
The staff member happened to be standing next to a boss who was being a dick about the exact same thing. The both of you can fuck off.