I saw my accountant long ago and discussed Bitcoin at length, and our assumptions based on existing law were pretty much exactly in line with this IRS guidance.
Can you explain to me the logic behind the taxable event of block creation by miners? AFAIK, entities that mine physical gold don't have a taxable event when they pull it from the ground, do they? Isn't the taxable event when they sell the gold?
The ruling is favorable to bitcoin miners, because you pay regular income rates (typically 30%) on bitcoin at the time it is mined, then capital gains tax (18%) on gains made while holding it. A gold miner has to pay regular rates on net income made by when it is sold. I agree with you it seems very similar, but the IRS is treating bitcoin miners better than gold miners, assuming an overall rising rate in btc and gold prices.
I can guess it has something to do with determining the point at which the gold is a refined product ready for trade. With bitcoin, it is ready after 100 confirmations on the block chain after being mined.