That's because DD doesn't buy any rights, it gets those for free so as to further transmit to DD Free Dish and Terrestrial viewers only (Those who don't have Pay TV), Ideally DD needs to block signals on its own as per court order, since DD isn't doing it, operators do it to avoid any controversy
Agreed, DSport's broadcast is horrible, but then the Court order is to protect rights of all those official Broadcasters who pay to get rights, unlike DD