Part of the problem is that the "disruptive" businesses (by design) often don't spend time thinking about or solving the difficult problems in an area, especially by coming up with working solutions to the problems that caused people to call for regulation in the first place. Many regulations can probably be replaced with something better, but they were often initiated by real problems, and it's important to understand what those problems were, and figure out how to avoid them or sidestep them. Many "disruptive" businesses don't have the historical knowledge or skills to do so, and are hoping they can just close their eyes and ignore the problems, which tends to lead to short-term success, but medium-term reoccurrence of similar problems.

You can see that with AirBnB, which I think is based on a good idea, but also utterly fails to deal with many of the actually hard problems in the space—those that involve things other than operating a website. Real-world problems led to hotels being regulated in the first place, such as health/safety and noise problems, and so far AirBnB hasn't done much to convince me that they even understand the problems in that space, let alone how to address them.

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).