There is an idea that international sports stars get paid vast amounts for very little work. In the case of the Pakistani cricket team it really is not true- the basic salary for international cricketers is £22000. While that is a considerable sum in Pakistan, it probably goes fast if you are travelling the world almost non stop in countries where the cost of living is much more that in Pakistan.
With millions of pounds being made through betting on cricket and so little being paid to the players it is not difficult to see why so many of their players were corrupt.
So the next question is why are they paid so little and the answer to that seems to be that their is no competitive market for cricket players- the money is largely in international cricket (the IPL is a positive step in the other direction.and players cannot simply offer their services to the highest bidder.
Despite football having teams from nations even more corrupt than Pakistan there are few credible reports of match fixing in international football because the clubs will pay players from poor countries what they are worth.