Kind of makes sense. The transmitters are connected to Linux servers as it's the best OS for this application. The network cards are mostly sold to consumers, who mostly have Windows PCs so they mostly have Windows drivers
This is a similar situation to a samrt battery charger developed by the company I work for, it's run by embedded Linux but all the software designed to interface with it is Windows only, it might be run by Linux but you can't configure or program it from a Linux PC, it has to be Windows.