If you believe bitcoin prices will in the next 10 years become worth 1000s or even 100s of 1000s of dollars like some people suggest, wouldn't you want to keep prices low, not high?
I would think you'd want prices to be high only if you were one of the lucky few that picked up 1000s of coins at the very early stages OR you wanted to sell your coins now.
I've been mining Bitcoins. So the higher the price, the higher I can sell my coins for. The electricity I paid for them is fixed, so the higher I can sell them (or trade them) for, the higher returns I get.
also the less bitcoins mined per miner (as a result of difficulty increase) the higher the price each individual miner has to sell at to break even