Jinnah was a lawyer whose 'proffers' were of a take it or leave it nature and which did not bind him or the State he envisaged in any way. Precisely because he was a lawyer, he did not sketch out any 'vision' of his own. That was not his business. His position in politics was as the Chief Representative of the Muslim League which demanded to be treated as the sole voice of the Muslims of British India. The core demand of the League is expressed in the Lahore Resolution which states -
geographically contiguous units are (to be) demarcated into regions which should be so constituted, with such territorial readjustments as may be necessary, that the areas in which the Muslims are numerically in a majority as in the North-Western and Eastern Zones of India, should be grouped to constitute “Independent States” in which the constituent units shall be autonomous and sovereign.'
Sovereignty means that the successor State, or States, would not be bound in any way. It is likely that Jinnah himself wanted equal opportunity, regardless of creed, and he certainly took the initiative to appoint non-Muslims to high offices or to entrust them with important duties- e.g. writing the National Anthem. However, precisely because Jinnah was a lawyer, we would be unjustified to say that Jinnah had a 'vision' which was subsequently betrayed. Had he really wanted to restrict what Pakistan could do, then he would have demanded a qualified sovereignty based on a pre-existing Constitution.
This becomes clear when you look at what had happened in Ceylon. There the minorities accepted a deal whereby there was strong Constitutional protection of their interests in return for ceding self government under universal adult suffrage. Jinnah was rejecting this route. He was not alone. All the minorities- including Dalit Hindus- rejected Gandhi and the INC at the second Round Table Conference. Though, in 1935 a Federal structure was envisaged, Jinnah and the minorities rejected it completely. Why? Even if constitutional safeguards of minorities was feasible, it was not what they wanted. Why? Jinnah's crucial claim, his 'vision', was that Muslims constituted a separate Nation of a sovereign type. Some Indian Muslim divines opposed this notion as 'wataniya'- i.e. a narrow Nationalism, incompatible with Islam which is universalist. However, once Pakistan was a reality, they would have to accept that 'hubb al watan min al Islam'- patriotism too is part of Faith. In other words, whether or not the demand for Pakistan was un-Islamic, once it existed as a sovereign nation, no Muslim had any right to object to it.
The precedent for what happened to British India- viz. its partition on Religious lines- was what happened when the Ottoman Empire was dissolved. Greek speaking Muslims went to Turkey. Turkish speaking Christians (presumably of Greek heritage) went to Greece. All this happened under the auspices of the 'secular' Ataturk. Indeed, at around the same time, Ireland was partitioned on essentially sectarian grounds. It seems religious identity exists even amongst those who aren't religious at all.
After Jinnah's death, some of his admirers were dismayed by the 'Objectives Resolution'. But we can't say this was a betrayal or subversion of Jinnah's intentions. He wanted sovereignty for Pakistan because he believed sovereignty was in the best interests of the Muslims of India. True, this left those on the wrong side of the border in the lurch. It is also true that Jinnah's 'hostage theory'- i.e. the Hindus would protect the Muslims in return for Muslims protecting Hindus- broke down immediately. It may be that Jinnah himself felt his 'vision' had not been realized. But, there is no evidence that he ever said so. It does seem, however, that Jinnah- like other leaders- was shocked by the scale of the violence and ethnic cleansing which broke out even in big Cities and prosperous, relatively well-developed, districts. By 1949, both India and Pakistan had hardened in their attitude to minorities. India forbade the re-entry of displaced Muslims who lost citizenship. The Indian Constitution would uphold things like cow protection and insist that the national language be written in the Devanagari script of the Hindus. In Pakistan, the situation of minorities was even worse and ethnic cleansing of Hindus from the East continued in the Fifties and Sixties.
Pakistan was slower than India in adopting a constitution and declaring itself a Republic. But when it did so, in 1956, it was the first country in the world to declare itself an 'Islamic Republic'. This changed nothing on the ground. In particular, the Ahmadiyyas (a sect viewed by some as non-Muslim), were not stigmatized. They held high offices and contributed much to the prosperity and advancement of the country. It wasn't till after the loss of the East Wing that Pakistan adopted an explicitly Islamist constitution with unfortunate results for the Ahmadiyyas. Still, the fact is Z.A Bhutto was promoting himself as a Socialist. It wasn't till the Army moved against him that, under General Zia, the State apparatus was made explicitly Islamist.
Why was democracy weak in Pakistan? The answer is that the East Wing was more populous and had a longer tradition of democratic politics. Thus, democracy would have shifted power from the West to the East- which was also earning more foreign exchange through the export of jute. However, in West Pakistan, the Civil Servants proved incompetent and corrupt. Furthermore, the rise of military men- like Nasser in Egypt- in other Muslim countries caused the Generals to think their own rule would be welcomed.
Since the army had good grassroots support through its network of ex-servicemen in the villages of Punjab and parts of the NWF, it could displace the embryonic class of lawyer/politicians in the West wing. However, it is important to remember that it was the aristocratic lawyer, turned populist, Z.A Bhutto whose machinations sidelined the Army and opened the door to Islamization.
The paradox of Pakistan is that it was Western educated lawyers like Jinnah and Bhutto who let the Islamist genie out of the bottle. Was this inevitable? Yes. There is a mullah in every village. People look up to them because they help resolve disputes and they teach the kids to lead a moral and spiritual life. By contrast, 'civil society' is relatively weak in the countryside. However, it must be said that West Pakistan made some great strides in primary education etc. Hence Ayub Khan's rule could generate quite fast economic growth and a feeling of prosperity in the West wing. Sadly, military adventurism was his undoing.