I think that what it ultimately comes down to is that the broadcasters want to restrict their audience in some cases for copyright reasons. They also want to have a decently reliable assessment of viewing figures so they can charge advertisers the appropriate amount.
The BBC is available across the UK essentially free, provided you have a TV licence, but the BBC charge other countries for the right to rebroadcast their programs. Satellites have antennas designed to restrict programmes to certain regions, even though they could easily and more cheaply cover the whole of Europe with a simpler antenna design.
It all comes down to how much money these systems can generate, as was always the case. As I recall, quite a few pubs installed large satellite dishes to receive football match broadcasts intended for continental Europe as the decoder cards were much cheaper than Sky's offerings in the UK. Lots of money ended up being paid to Sky by said pubs by the time Sky's lawyers had dragged them through the courts.
It's all about money. Even PPRuNe has adverts!
