Chemist's reply: Metal has a polar surface to which polar water molecules are likely to stick when they encounter it, especially if the water molecule is cold or made to be as soon as it hits. Rubber and plastic materials are more like an oil, and are nonpolar on a molecular level, compared to metals and water anyway. So when the polar water molecule encounters the cold plastic/rubber it is more likely to bounce off AND the plastic/rubber has less heat contained in it per square inch of surface area, and the water does note get cooled off when it encounters it.
Lay terms: imagine a magnet hitting a metal wall versus a wooden wall.
Quantum Mechanics, sticking probabilities. Gawd I luved it...