window centric vendors

One of the big annoyances for people like me who do not use Windows (I use the Kubuntu Linux distro) is the number of web sites that use Windows only features. The web sites for ABC, NBC, and CBS for example require windows media player ot view their videos. These sites have effectively removed Linux users from there set of potential viewers. I don't understand why major corporations would not take steps to ensure the widest base of potential users of their services.