I'm not worried that much about software bias - I feel that a lot of good could be achieved with software clear enough for all sides to accept it represents their interest in an ok-ish way.

What I'm worried about is this: technology has always been a force multiplier for those who wield it. For now it's us (maybe in the future it will be a superintelligent AI, maybe not). Even if we manage to write a pretty unbiased governing software, how are we going to ensure that it isn't subtly manipulated by some interested party? And can we ensure that while also making the system extensible, so that it can cope with the demands caused by the impact of ever-progressing technology on our societies? It seems to me that the two goals - a system above humans and a system that can evolve with us - are fundamentally incompatible.