Limiting supply in my opinion would not be healthy for the platform long-term as people with the highest amount of steemit could crash it if they ever sold off a majority of their holdings much like the domino effect bitcoin is having from the sale of bitcoin by Mt Gox to pay off it's investors.
A limited supply creates stability in a coin, the more strong hands the less brutal the crash.
Also the bigger the marketcap the more money you need to crash the price, limiting supply increases demand and so increases marketcap.
RE: Can STEEM ever become a reserve currency?