Why is my licence fee (basically a very regressive tax) being used to apply for further government-granted monopolies that can only be used to tax (or worse prevent) other corporations from delivering video services? What benefit is this providing the people of the UK?
Well I'm not sure the argument is any different than for the entirety of BBC Worldwide. Generated revenues from licensing and cost savings from cross licensing can make the license fee go further.
Pursuing patents isn't cheap especially when it is done in US and Europe as in this case so I expect someone foresaw the possibility of some return from this. There was some belief also that patents or at least applications were the formal way to get prior art into the record so that the ideas would not be patented by others in the future preventing the BBC from using them. I know that legally any publication becomes part of the prior art record but at the time of application for a patent it is principally the patent databases that are searched so there is some truth to the point that a patent is the best prior art.