Steem already is a crypto token that can be exchanged. I get the importance of Steem Power (SP), and I think that's really cool. (Actually I'm not totally convinced of why we can't just use Steem instead of Steem Power.)
But what is the usefulness of Steem Dollars? So it's pegged to the USD, so what? Steem is exchangeable to USD already. It just makes the whole process of joining and participating in Steemit more complex and confusing for new users.
Simpler is better! But, maybe this is all necessary and I just don't understand why.