Reasonable thinking, but i think there is a small flaw on your logic, i would like to discuss:
You say:
If a person made $1000 or even $100 that person would be motivated to post much better content to gain more and more upvotes
But what If one Guy start to get this reward with shit posts, 10 times , with one vote (and only vote for that one Guy account) from a fat whale newly created that bought tons of SP, that give $200 per vote ?
This is possible. And is pretty easy with enough money, since you can create any amount of accounts with only 6 STEEM.
That Guy wont need anyone elses votes to get a daily $ 2k reward.
Incentivize to post and curate good content is needed, but there still need a way to properly contain system exploits.
The Free market Idea is a good one in theory, but extremely hard to achieve due to human greedy Nature.
I was going to write about this but the post got a little too long. Here is a quick version. What if we make a dynamic cap based on unique upvoter per week. If the cap is calculated based on $5 revenue per unique upvoter and for the sake of ease consider all upvotes are self-upvotes, it will take the account+199 bots to make $1000 per week and +999 bots to make $5000 per week.
There are no perfect systems. But we can make some tasks easier and some harder.