Qortal's biggest failure is that people with level 5 accounts with sponsorship ability almost don't have the ability to promote qortal. Or do not actively promote the growth of the qortal community.
A person with a level 5 account mints 18 times more coins than a level 1 and 2 account.
I think these reasons will make qortal very unhealthy.
I was offered a sponsorship within a few days of participating in the community, so my experience has been different. If it was POW or POS, I'd either have to invest in mining equipment or money in my stake or both. In Qortal's Minting, my only investment is my time & engagement with the community.
Not a bad trade off for no monetary investment, even if I earn 18x less. As each day progresses, the gap between minting rewards slowly narrows. In a sense, this is no different than anything else, the early adopters enjoy the most benefits. Ultimately, time will tell.