Still don't get it even after reading it. What is the mechanism that creates the guaranteed interest? Is it like a ponzi thing or what? Also from that part of the thread sounds like the blockchain for it needs some fixing?
Basically what it means is that the stake reward / interest or whatever you want to call it is what you get for leaving your wallet running which forms a network along with many other wallets that confirms and verifies transactions as well as secures the network. That is all. It's similar to miners that have specialized equipment to mine bitcoin POW (proof of work), which confims transactions as well as securing the network, The bitcoins that are rewarded to the miners are just a thank you for securing the network.
In the case of a POS (proof of stake) wallet, you don't need specialized equipment. Hope that makes sense.