Yeah, okay...I'll bite
The problem is that we always notice the ones that wind us up, not the ones that do everything the way "we" would do it.
Added to which, we only ever see things from our own perspective, not from the other person's.
This afternoon, whilst driving to the stables, I met a large contingent of cyclists (I assume a sportif or something was going past, they all had numbers). Of the 40 or so cyclists I met, I saw one do a really silly thing and return onto the carriageway from the pavement where she and two others had stopped. That wouldn't have been an issue had she not cycled out right in front of the one car on that side of the carriageway, which had to brake sharply to avoid her. Ten seconds' wait would have left her a completely clear road.
I also watched at least 5 cars perform extremely unsafe overtakes, squeezing past with less than a metre-often less than 6 inches, to spare and one who hadn't completed the overtake before swinging left into the cyclist they hadn't quite overtaken-who thankfully managed to avoid being driven through by braking sharply and veering further left.
I chose not to take my horse out on the roads as they were passing quite close to the stables and my horse is still a little bike-phobic, especially when they're going fast. Otherwise, chances are that car drivers would have passed me too quickly and too closely on at least 4 occasions-based on previous experience. Considering the amount of cyclists, chances are that one or two would have overtaken me unsafely too, since unfortunately not all cyclists know how to safely overtake horses either
I still remember sitting behind a cyclist while driving a few years ago. I was a bit frustrated that they didn't get into the gutter so I could squeeze past. I didn't get het up about it-it only held me up for a few moments, but despite being a vulnerable road user when horse riding I couldn't see how unsafe that would have been. I couldn't see it from their perspective, because I didn't have the knowledge or experience to comprehend.
A certain percentage of humanity behaves poorly. Some of them drive, some of them cycle, some of them horse-ride, some of them walk. Some do more than one. But sometimes, what we consider to be idiotic behaviour is actually safe and sensible behaviour, we just don't know that it is.