One reason I see is because bitcoin is already being used by people as a means to get more of their local issued currency by means of speculation and trading. If we kept the idea of 1 BTC = 1 BTC and people haven't discovered its speculative properties, we may have flourished as a strict P2P currency system without government intervention, however since people are using bitcoin to get fiat and vice-versa, that's when governments feel the need to step in. With this, regulations are somewhat painful compromise we as a community have agreed to ever since people exchanged bitcoins to fiat, and that is back in 2010.