A thing I don't understand about this article: "vertical integration…was the old Henry Ford model and later, General Motors'. That approach has gone down in automotive history as a colossal failure"

Because clearly when we think about the role of pre-Baby-Boom Ford and GM in the history of the automotive industry the first term that comes to mind is "colossal failure"?

Also it seems contradictory to say "Tesla shareholders" don't "despise [the] deal" and then point out that the stock price dropped 10% when the deal was announced. What determines the stock price, if not the previous and current shareholders? Gremlins?