I wasn't ever hopeful Mike-three initial posts and no follow up so far. It's not uncommon but we never get an explanation
There is a strong cross reference with the current thread in Forum Announcements "Members Last Activity". I think it would help if we weren't quite so helpful, looked at the history and waited for a response initially [especially on some of the repair enquiries] but not everyone agrees. This is a more [very] general topic so [ironically perhaps] it has inadvertently promoted a very interesting thread anyway, as it doesn't rely on OP participation to progress.
Dave
Crossed posts!
You are right that it doesn't matter in this particular case Peter, for the reason I gave there but it can be very frustrating in other situations you know. Beyond that the simplest overall answer to your question would be that this is a Forum!
Going right back to David's comment about the UK Dual Standard System [post 20*] from this distance it looks like a bit of a dog's breakfast, although interesting in terms of the adaptations that took place at the time. Post War "make do and mend" perhaps! As the main benefit of receiving on 625 lines was to gain BBC2, a lot of detractors couldn't see the point of all the silly intellectualism [Jazz 625, Hendrix and Ringo Starr turning up in the middle of Late Night Line Up etc] and stuck to 405 for as long as they could. There was a similar attitude in 1982 when Ch4 debuted.