Um. Let's say, it's a good thing for us and earth's space mechanics and weather that the moon is like it is right now.
Some say the earth would spin faster if the moon wasn't there at all.
Not sure how big the effect of space mining could be on moon's mass. To be fair I'm more concerned that someone will use the moon as a giant billboard some day. :)
Pff. You really think food grows on trees?