My response to the Wolf to how and why Judaism has any meaning if the foundations are not factually true:
If we can turn some of the best things of Judaism and find new and independent reasons for perpetuating them then we don't need Mattan Torah or God commanding them to be done.
You think people in America celebrate Christmas and Holloween because of religious reasons? Some do. But the rest?
A common custom of Shavuous is to eat milchik meals. You could go through three dozen people in shul and not come upon one who knew why.
There is value in Judaism. And many aspects of it can and will survive even when the original reasons fall. As Judaism is today very few rituals are carried on as they were originally meant. Reconstructionist Judaism is really just a movement along these same lines.