YANBU
Runners on roads were a menace before lockdown.
I used to commute by car, 20 miles each way, on narrow, bendy, hilly roads, surrounded by trees, with no hard shoulder (lovely countryside!)
I had to share this road with other cars (commuters, and leisure drivers), cyclists, horse riders, tractors... Could be tricky at times, as everyone went at different speeds, and the road was so narrow and bendy that passing was rather hazardous (you had to be patient, and moderate your speed)
But at least we would all be going in the same direction when using the same lane. So it kind of worked, if you paid attention.
Runners, however... Quite a few times on a sunny morning, I'd take a blind turn at very moderate speed, to find myself faced with a human being running straight towards my car, showing no sign of slowing down, changing lane, or stepping off the road. As they zoomed ever closer, I would have to swerve to avoid them, and once narrowly missed a car which was coming from the opposite direction.
I would never have chosen to overtake in the middle of that zigzagging blind turn. If there'd been a cyclist, or a horse, or a tractor, or a leisure driver, I would have adjusted my speed (which was already low, knowing such blind turns can hide surprises, including stationary objects such as fallen branches, or a flooded section), and patiently driven being them at snail pace, till we reached a straight section where I could safely overtake.
And if the obstacle had been stationary, I would have stopped there, then decided exactly when to overtake, based on oncoming traffic.
But when the obstacle is moving towards you, at non-negligible speed? If the person was walking, there would be time to think. Typically, walkers have enough sense to stop, and step aside a bit, so you can pass them easily.
In comparison, contraflow runners are suicidal! Given their speed, it would make more sense for them to behave like cyclists, and move in the same direction as the lane they occupy. The whole point of going contraflow, is that they can see cars coming and stop. If they're not going to stop or move aside, they might as well be moving in a direction which minimises the speed of collision...