You seem to have a funny definition of the word "fair". As far as I'm concerned "fair" means "if you do more work, you get paid more". How is it "fair" to pay miners equally regardless of how much work they do?
Maybe the word I should have used is "Even" or "sensible". For BitCoin to go mainstream demand will need to be there. As it stands the only people with any BitCoins to spend are a tiny amount of the population. There is no demand for BitCoin services until lots have people have them to spend. Demand will dictate supply.
As it is, Amazon and other major online players don't have to support BitCoin because nobody has any anyway. It's not good for BitCoin to just have a few people hoarding the coins.
Give the miners a more even return and more people will have spending power to drive up demand. I'm not saying it should be shared equally just more evenly. Miners who have invested more would still have the lions share. An analogy could be that a slow miner would still get about the same as the work he's putting in but he also might have a slim chance of finding a huge nugget from time to time.
People might end up sitting on a heap of monopoly money if it doesn't go mainstream and every miner is helping BitCoin to go mainstream