alt Hacker NewsThe BBC can be very pigheaded, i.e. offering no incentives for people coming forward.
Even without losses, they have a trackrecord of stockpiling a lot of old content but not making it available to the public. I doubt this would happen to Doctor Who but it would elsewhere. You would think with streaming that the BBC could make a lot of obscure old content available, but they don't.
That's not just the BBC, it's any broadcaster, because it costs nonzero dollars, time, and effort to move something online that they have no idea whether anyone cares about. Our national TV archives are like that as well, tons of stuff in vaults but if you want to see it you need to contact them and ask for it. I did that for some zany 80s comedy that they had listed but wasn't online, a few weeks later it was online, they just needed an indication that there was some interest in it.