If you are old enough you would know that Ayub Khans’ era was even more peaceful and far more liberal and the period before Ayub even more so.
Any period where dissent in any form is crushed ruthlessly will be peaceful. Afghanistan under Taliban was also peaceful and free of even petty crime. But what is use of peace where even women are beaten up for not wearing full Burqa? Graveyards are tranquil and peaceful places but would anyone living creature want to reside there?
During the Zia era I was frequent visitor to Pakistan because both the parents were living. Indeed it was peaceful because opposition in any form was crushed. However, look at kind of society it created; a mob of the outwardly pious worshipers burned down the US Embassy in Islamabad in November 19179 on mere rumour! In actual fact the Holy Kaaba seizure was purely the work of Saudi born fundamentalists with US having no involvement whatsoever.
Zia created a bigoted & intolerant society where people would kill a totally innocent person without slightest remorse. I have experienced Pakistan before, during and after the Zia era. In my view Zia was the worst calamity that befell Pakistan.
Unlike Zia supporter, I believe in human rights and not forcing my views on other with a shot gun; you are welcome to love & admire the bigot Zia as hero of Islam as much as you like.