On occasion I've mentioned the benefits of using a circular polarizer when shooting certain flowers. These two images (cropped from a larger image) demonstrate that. Shot seconds apart - once with the polarizer rotated to have no effect and then rotated to have maximum effect.
The reflection problem seen when no CP is used cannot be cured after the fact in Photoshop. In the glare areas the image detail is irretrievably lost - it's *blown out* and no amount of image editing can bring it back. (Sure, you can *fake it* via paint/clone/etc but the original data is gone.)
The moral of the story is to be aware of potential problems and solve them in-camera whenever possible. Getting the best image possible in-camera gives better results than to grab any old shot and "fix it in Photoshop" later.