Could BitCoin ever be backed by Gold or some other commodity in the following fashion? And would it be desirable to do this?
Assume for the sake of argument that all 21 million coins were in circulation as of just today. Suppose some rich reputable entity (Bill Gates or the Pope) bought up all bitcoins at market price (29 cents) for $6,090,000.
This is a misunderstanding. The current market price for one bitcoin is around 0.29 USD. If you want more than about 100 000, you are already paying 0.5 per bitcoin. If Bill Gates and the Pope want my last bitcoin, they will have to part with their last dollar, and I will have my own state in the middle of Rome. What you suggest is impossible.
But, of course, anyone could back Bitcoin with gold by offering a gram of gold per bitcoin, or something. Guaranteed. In that case one Bitcoin will be backed by one gram of gold, but not tied to it. The value of one bitcoin will be higher, since bitcoins are easier to use.