I'm a big believer in the fallacy of Chesterton's fence, so I actually agree with what you're saying. My point is that disruptive businesses serve as the 'reset' button for these industries. The problems get ignored at first, then rediscovered, and finally re-solved in a (hopefully) better way. Eventually, the cycle comes full circle, and the disruptors become the disrupted.

It may not be the most efficient system in the world, and there are definitely casualties along the way, but it does seem to work more often than other approaches (at least that I'm aware of... would love to know about other approaches that have a similar/higher success ratio).