The first are unbacked, fiat like bitcoin is now.
Bitcoin is not a fiat currency. Fiat means imposed using force, usually by governments. Bitcoin is a voluntary currency.
The others would be backed by something like CPU shares in a big grid, or space in a massively replicated filesystem.
Since both those thing are not scarce, why would you back a currency with them? For example, do you thing anyone woul trust a currency backed by leafs? No, because leafs are very abundant.
This post will purely discuss the former. I am a computer scientist, not an economist and recognize it's debatable which is superior. It does seem clear though that the power to arbitrarily control interest rates and inflation is a very good one when used responsibly.
Clearly you need to give it more though. How do interest rates affect the economy? Is is possible for one person (or a group) to centrally plan interest rates? Its not a problem of corruption, it is a problem of limited information.
So here is how that can be done democratically.
And what would be the result of "democratically" selected interest rates in the economy? How would peple know with their limited information and their personal incentives what are the interest rates needed?
Look at a corporation raising capital, say they get a
pre-money valuation of $4 million from a VC for their 1M shares, so each share is worth $4. The VC wants to buy 500k shares. The corporation issues 500k brand new shares out of thin air and sells them to the VC for $2M, which then become the assets of the corporation. So the corporation now has 1.5M shares. OMG INFLATION right? No. The corporation just got $2M in assets, and so has a
post-money valuation of $6M, so it is still worth $4/share. That is not inflation.
That is not price inflation indeed, but if that were to happen with money that would be monetary inflation. Why is that bad? Because it creates bubbles. Check the 20's. There was almost no price inflation, Irving Fisher said the Fed was doing a great job at managing the monety supply and creating the correct monetary inflation to keep prices stable. But hiding behind the price index there was a bubble forming in the stock market due to the monetary inflation that popped in the crash of 1929.
Having some price index constant is not a good monetary objective and does not matain a healthy economy.
2) For stable prices, and elimination of the "ponzi-scheme" feeling, coins should cost the same to produce. As it is now, the reward for a block is the same 50BTC it was in 2009, but requires 1M times as much work. This is the fundamental reason for gross price instability, and the reason bitcoin is perceived as a ponzi scheme. In other words, it's obvious that prices are instable now, because different coins cost different amounts of money to produce. So it's easy to stabilize prices: make all coins cost the same to produce.
This is very wrong. Bitcoin is inestable because its a small market and when new money comes in it has a big influence. If you start your new hashcoin it will be unstable as well, no matter how much does it "cost" to produce.
Also, let me predict that your hashcoin would be accused as well of being a ponzi scheme, because those acusations come from not liking Bitcoin and wanting to attack it some way and from envy, not from really thinking that it is a ponzi scheme.