I did it for two reasons. I could use the extra money. But not that badly, I've done well with Steem Dollars. But I mostly did it to learn.
I have high hopes for Steem's future. But I believe if a huge chunk of your wealth is in one place, that is a bad idea. I can take that cash and put it elsewhere. So this is also an investment decision.
Plus I generate a lot of Steem Power anyway by commenting and upvoting. I've gain more Steem Power than I Powered Down. That seems to be an all-win scenario.