The arguments against coasting in neutral, when people try to make them, are that you might go too fast and lose control, or that you end up overheating and wearing out your brakes. The former presumes that your are hell bent on not engaging the engine and are going to coast all the way to the bottom of a steep hill no matter how fast you end up going, and the latter was based in a time when cars were equipped with drum brakes that could barely stop a car without fading and also presumes that when the car gets going to fast you are riding the brake rather than re-engaging the engine.
If you are going down a gentle grade with the engine and transmission engaged on a closed throttle, there really isn't any more fuel being burned than idling in neutral. So there isn't a whole lot of point in coasting. I do coast up to stop lights and put the transmission in neutral to save the slave cylinder now while sitting stationary. If that causes a fractional bit more wear on the brakes, so be it. I can replace a lot of brake pads and rotors for the price of having the transmission pulled and opened to replace the slave cylinder.