Possibly both of the above. I think my personal bubble is smaller than seems to be the *ahem* norm amongst those who frequently publish their videos as many of the issues which others perceive would be classed as non-events for me. I'm not sure whether that is, as some suggest, because I ride assertively or whether that is because I ride in east Berkshire and London or whether that is because riding a motorbike has affected my perception of close-passes.I think you are either very lucky in where you ride, or you have a very high threshold for the amount of idiocy that is required for a driver to be considered a plonker.
I guess it also matters what we consider to be "plonker" behaviour.
IMO, people are annoying when they exhibit the "must get in front" mentality, when they attempt to block an overtake by hugging the pavement (without considering that I'll pass stationary traffic on the right) or when they don't dip their lights at night because I'm "only a bike". Those are annoying but their aren't life threatening.
I consider a plonker to be someone who does something which is dangerous. In a year of commuting 20 miles a day roughly three times a week, I can only think of one plonker who overtook a car which was about to overtake me. And I can think of only one plonker when I've been out for a ride and not commuting, who pulled alongside me approaching a roundabout then tried to squeeze me onto some pedestrian barriers.