How do you engineer something for the very distant future and get people to care about it today?
We are trying to get people to think long-term, because civilization's shortening attention span is mismatched with the pace of environmental problems.
Symbols are important.
The more we highlight and blend in with the most spectacular features of the mountain, the more memorable a Clock visit will be for the time pilgrims.
It's very important that we adapt to the world on the long-time scale as well as the short-time scale.
If you want to see humanity move gracefully into space, you have to accept it's going to take a while.