Yes 10% a week is insane growth, but not for those who are under 500 SP...it actually is very doable. A couple decent upvotes on a comment or article will add that.
I doubt it takes a decade...I think you will see laughable numbers by the end of 2018.
We are in for a huge year in my opinion, not just for STEEM but crypto in general. Nevertheless, I expect STEEM to excel greatly.