From my years playing Minecraft, it's probably got a lot more to do with the layout of the upper room. Like you don't want your spiral ending toward a wall, you want it ending toward the room itself.

It might just be because architects / builders copied each other. There are loads of little infrastructure details that vary from country to country with very little reason for the difference other than "that's how they are here". For example the gaps in American toilet stalls, or even the shapes of the toilet bowls - way shallower in the US than the UK. Why? Just tradition I expect.

One comment was

“it was easier and more natural for a right-handed architect to draw plans for a staircase with a right-handed spiral”

There’s also the claim that 30% of staircases are anti-clockwise. That’s a lot for any statement of always or mostly clockwise.

You can fall down positioned upwards or downwards.

Unless walking backwards, it is normally more common to trip and fall over forwards; when walking upstairs, you could just fall on your hands, since there's stairs in front of you. It is very difficult to trip and fall over backwards, specially when walking upstairs.

Falling upwards generally comes with less potential for injury. Falling backwards when going up is probably about equally bad regardless of clockwiseness.