Disagree in the general case. Instability costs money, and incumbent players with better access to capital can survive more easially. On the other hand, stability in regulations make it easier for a start up to derisk themselves as there will be a well built up series of case law around the relevant regulations.

Now, if you mean technology instability, completely agreed. That's where innovation comes from.

I think Uber's a perfect example. Taxi regulations either have been stable or essentially unenforced for decades in most places. This gave them the opening. However, everyone getting a smartphone in 2010-2011 is what really blew the doors open.