The misguided busway is a very peculiar environment and I think it is important not to generalise on the basis of one particular experience in that very peculiar environment.
It's an environment with which I am quite familiar, being similar to a Milton Keynes Redway. Yes, those don't have buses down one side, but some do have an equivalent (arguably worse) risk of falling onto a 70mph dual carriageway.
The footpaths/cycleways adjacent to the busway were not part of the original design. They were added to stop both pedestrians and cyclists from using the busway itself. The busway is mostly built on old railway tracks, with an alignment to match. The footpaths/cycleways can be very busy with a mix of pedestrians and cyclists, and are not really wide enough for the level of traffic. Pedestrians using the busway frequently mostly know that they have to keep an eye and ear out for cyclists: there's lots of them and some will be moving quite fast because of the railway alignment. For pedestrians it is more like walking in a road than on a footpath and needs to be treated as such.
Of course I would not consider a close, high speed pass appropriate if I was walking on a country lane. It sounds like you're justifying making close passes at speed. This cannot be justified under any circumstances, just like cars doing so to cycles cannot; if there's not space then it's necessary to slow, ring one's bell (or shout if one doesn't have one) and pass at little more than walking pace, just as if there's not space for a car to pass a cyclist at a minimum of 1.5m spacing then they should slow right down to make a closer pass safer*, or in some cases not pass at all until there is space.
Interestingly the MK Redway Code specifically states they should be used "as you would use a traffic-free country lane".
It was the hypocrisy here that got me. The lycra-clad campaigners rightly complain about cars close-passing, then they do it to pedestrians...
I use the footpaths/cycleways adjacent to the busway quite frequently. In my experience pedestrian behaviour is just as big a danger as cyclists. That includes groups walking three or four abreast blocking room for passing, and people immersed in their phones/music and unable to walk in a straight line. Cyclists using the busway frequently mostly know that they need to anticipate such behaviour.
True of the Redways too, however I was walking all the way to one side, so the cyclists involved had a good 2 metres of space. Even if they were using the "primary position" the pass would have allowed a 1m spacing.
The very peculiar environment has turned out to be quite dangerous, with 2 fatalities on the southern section where people (one cyclist and one pedestrian) have fallen into the path of oncoming buses. Nobody knows how many people have stepped/fallen into the busway without catastrophic consequences. I avoid using the footpaths/cycleways adjacent to the busway at times when I anticipate that they will be busy.
They weren't particularly busy to be fair.
* Some "militant cyclists" don't think the car should pass at all if 1.5m isn't possible. It probably shouldn't overtake, but this rather disregards passing oncoming traffic on single track roads, where the right thing to do is for both parties to do their best to accommodate the other in less than ideal circumstances.
