There are more reasons for Taiwan's economic failures

Comments on J Bruce Jacobs "Taiwan’s democracy grows stronger as KMT falters", 7/01/2016

In the second last paragraph, it is stated: “President Ma’s China plans have fallen apart. His Economic Cooperation Framework Agreement, signed with China in 2010, has not produced the forecast economic prosperity.”

What are the main reasons for this failure of producing the forecast economic prosperity? Do they have anything to do with the slowing Chinese economy and difficulties/challenges international economies have faced?

Realistically, would Taiwan be better off or worse off economically when it have a better relationship with China, given the size and its regional and international role of Chinese economy?