Zia-ul-Haq's actions had visible damages back then and have visible damages now. Exactly what, by your logic, were the visible damages resulting from Jinnah's action? Just when exactly will those "good things" reveal themselves? I mean its been 28 years almost!
And how do you propose that we find a solution if people aren't willing to accept the facts, ascertain the root cause and assign blame first? How do you treat if you not first diagnose? A lot of things acted as catalyst for terrorism later on however Zia administration's action provided the ideology and resources (dollars, heroin, arms) for them. It begins with Zia in 1980's, he's not merely a part of the story. Something, which people mistaking the said leader for being Commander of the Faithful often forget, all while considering the criticism on a highly flawed mortal being as being on the great religion of Islam. Forgetting that the ruler's action were motivated by the desire to "crawl out" of the international isolation he found himself in, when he ceased power and to grant legitimacy to his rule.