In an ideal world the Fed would not "set" any rates - it would be up to the market. However, the risk is there could be more volatility on the short end without the Fed 'anchor'. A compromise might be to greatly increase the target range from 25bp to funds target rate +/- 200 bp, lower bound 0.00 thus making a bounded floating rate. That might also require a shift in how lenders set rates on very short term debt to some type of period average, ie 3 or 6m average rate.