You guys forgot to mention network security (look up the 51% attack) What is the cost of security and how do you even go about measuring it?
This is the only comment that added any value whatsoever to the notion that we should have as much Hashing power as we do.
Your argument is crap because you rely on "feelings" and "ethics" when human beings and the market are driven by pure capitalism and greed, especially where BTC is concerned.
You say we don't need so much hashing power, that we are wasting electricity with it. I say I'm getting my mining proceeds and paying my power bill.
If there is money to be made, even a little, people will do it. If there is not money to be made, people (probably) won't do it. (unless it's fun, and mining kinda is fun
)