Real-life systems generally have multiple agents with different incentives and different amounts of power. Usually, if a system works in particular way it's because this particular way benefits someone with power (often, at the expense of someone without power). Real-life systems also tend to be quite complex with many relationships not visible on a cursory glance -- what looks like a Pareto improvement to you might look like an attack on an established right to someone else. This is not to say that existing systems can't be improved. But there are reasons why they are what they are and unless you understand these reasons and have enough power to apply to leverage points, talking about incremental Pareto improvements is not likely to lead to anything.