Maybe it makes sense if the whole device needs to be installed in an inaccessible place frequently and most people would be unlikely to take advantage of a wired connection. Or maybe their statistics of the common usage of the equipment actually support it. Or both, I don't know.

In any case, since you're already being sold $2000 worth of equipment for the absurdly low price of $500, I'm not quite sure that a complaint about some adapter is in order.