The difficulty in suggesting or challenging Scotland post exit from the UK is how long and how intertwined the economies are.
Plenty of businesses are in Scotland because of the union and would not necessarily survive or remain that way post breakout.
Specifically as its my area of expertise, financial services. There is no reason (just like London) that they could not move, certainly some would, or would change their scale.
Some government based departments and also some big UK based buisnesses, such as Sky, employ more in Scotland than Scotland would support (or require) as an independent.
Thats not to say they would move, its just possible that over time the may rebalance.
I am sure Scotland would be successful on its own. What I can never reconcile is how leaving the UK (cos of dem imperialist overlords) is any different to being a very small fish in the sea of the EU is some magic pill for prosperity.