Some of your points are good, but others to do with the economy don't really take into account how this economy comes about.

The money that people get from upvotes comes from investors money. Without the investors we don't have any money.

The investors take a risk in investing in this form of cryptocurrency social media. There was no guarantee that it will succeed. They could lose all their money.

The magic behind the system is Delegated Proof of Stake (DPOS). This is a flexible, scaleable, low energy way of running a blockchain. It is a departure from Proof of Work, which requires huge outlays in mining equipment and electricity costs. DPOS requires people to have a stake to guarantee the integrity of the system. Without the stakeholders their would be methods of gaming the system that would cause the system to fail completely.

This is the technology we have bought into. New technology is on the way, some of which will improve the Steem blockchains functionality. For now though, this is a system that is working.