Probably a financial decision. Many NLS & NLN teams only get 4 or 5 hundred pitching up for their home matches. How many of them are going to fork out best part of a tenner to watch a poor quality stream of their teams away games?
Especially on nights if they have Sky/TNT packages they have already paid for and a Spurs vs Man City type game is there to watch for no extra cost.
Even if 20% of the fanbase tune in they would struggle to cover costs.