"Why did the community spent years on marketing & improving Steem, just for the useless founder to get a nice payday?"
The platform was always designed for that purpose. It was obvious.
If this was about attracting users with a well designed platform meant for user experience, the issues would have been addressed back in 2018 when these issues became undeniable.
Remember when the whole game was buying votes from bots?
Don't worry, Justin has an excellent track record of making good profits while sucking the life out of his investments.