Because it breaks down if we use another example. Would you want to solve a rubik's cube that was pre-turned so there were only 3 flips left to complete the cube? Changing the state of the activity (adding bolts/belays/ladders/etc.) is not in the spirit of the event, just as almost finishing a rubik's cube for someone else isn't in the spirit of actual event.

Put a different way: the climb becomes the bolter's experience, not the mountain's experience. It is no longer intrinsically mountain climbing, it's hiking.

There is the "Leave No Trace" principle where you do not leave anything behind.

This is why you see in trad climbing the lead will place cams and nuts, while the last in the group on that pitch retrieves them.

I don't think it's just a matter of ethics - some legal entity owns these mountains (park authority of some kind?) and drilling holes and placing bolts done without the permission of the owner sounds like vandalism to me.

I am of the belief that we should leave a place better than we find it.

When litter is in my path, I remove it. To do otherwise would go against this fundamental principle.

Natural places should be protected from the widespread exploitation by humans. We are destroying the entire planet. Why can’t we protect the places we have long agreed should be protected? Enough with the anthropocentric BS already. We are a part of the world, not separate.

If you are being serious; read the tower for much more context.