Well, to me that is the same thing, because since it was proprietary, Steve Jobs and Apple could not control it (and maybe improve it and adopt to their standards) - so they rather threw it out. (not that apple had a problem with proprietary tools, justs with proprietary tools not under their control, in a vital position)

If the Flash player would have been open in a way, chromium/webkit is, with many top players working on it - it very likely would still be around and maybe even dominating, as it was way superior in terms of features and more importantly, it was not a mess to work with, like HTML still is.