While the above is all true, it does not take into account that the market for mining gear is a significant one for the use of bit coins. So to the extent that that market is influenced by the hash rate so to will the bitcoin price.
Spend some more time around here, and you'll slowly start to realize that this just isn't true.
It's almost completely parallel to the old gold rush adage that it's better to sell the shovels than to mine the gold. That's essentially what you described above. But it has practically zero effect on market price.
The topic of coins "hoarded" by miners indefinitely...sure, that does play an indirect role on the market price. But the whole "price vs. hash rate" discussions here are typically way off the mark.