Pakistan Army's interference is the single biggest reason. All the corrupt civilian politicians are products of army. Army use corrupt politicians giving them turn for power where they toe army's line. Army would not let corrupt politicians get due punishment. Its a cycle.
My knowledge of internal politics of Pakistan is solely as an outside observer. While corruption is an obvious evil that we are stuck with in the subcontinent, some of the more competent ones have either been a little corrupt even though in most cases maybe not them personally but people around them.
I would say biggest financial scams happened in India in the early-mid 90s but that was also the time when Indian economy was opening up to what it has become today. I am not saying corruption and progress are directly related but sometimes this corruption thing is just a crutch for clueless politicians. You can always work your way around it rather than saying that nothing else will be done Until corruption is eliminated or it is the sole agenda. You think American or British politicians dont receive Kickbacks?
While I understand the glamor in someone who wants to eliminate corruption but there are so many other moving pieces as well that take to run a country.
I think Nawaz Sharif whatever the allegations against him are, is admired in India relatively speaking compared to other leadership of Pakistan because he actually made an honest effort to make peace with India and was ready to work to resolve major issues.
In fact he tried to work with government that is presumed to be hardliners and right wing which is BJP on both occasions. Also add the fact that he seemed to be a decent administrator.
I know Pakistanis hate Modi and I can understand that however I always see this jab that Modi is a chaiwala or whatever and Imran is an Oxford or was it Cambridge graduate?.
However the deal is that Modi started of at the lowest level possible, learned all the ins and out of politics on the job, eventually became a chief minister and then the prime minister of India. It was organic growth. Just because someone is an Oxford graduate and has done well in his profession doesnt always translate to great diplomat, politician and administrator.
The criticism of Imran is because the perception is he is a total proxy of the army but with Sharif or Bhutto and obviously with the generals/presidents we never got the same vibe even though they might have been.
The big takeaway from what I am trying to say is subcontinent doesnt really need these big charismatic leaders but they need capable administrators who can may be let a few things slide but at the end of day somehow get even half the job done.
Ask anyone who Indias greatest PMs were and I will bet most Pakistanis wont even be familiar with some of the names. Narsimha Rao and Shastri come to mind. Vajpayee obviously is well known in Pakistan due to the whole Lahore bus yatra but even he was never considered a charismatic leader but just aN excellent orator and admin. Same can be said to a lesser extent of Manmohan Singh who despite being somewhat of a proxy at-least was component and a scholar in his area of expertise which was economics which was useful.
I would say this is why may or may not be exactly Nawaz Sharif but someone who can work around silently in the background ,let army do their thing if it is unavoidable but still can somehow get even half the job done is needed in our part of the world .
I am not saying corruption is good or half-a**ing things is the way to go but that is why India is doing better than Pakistan also the reason why India has not achieved its full potential because of the half-a** ing things at times.However this is my theory why India has done a better job than Pakistan relatively speaking.