The reason power plants in Pakistan probably require this kind of financing is because Pakistan doesn't have the industrial capability to make the equipment that you need to build a power plant, so, dollars are a requirement.

Power companies in Pakistan also don't have easy access to international money markets, and thus, it makes sense for the government to back those strong currency loans as a subsidy on infrastructure.

This is not exclusive to Pakistan, this is the routine of infrastructure financing on developing countries. J.P. Morgan is not really eager to lend money for PakiPower Incorporated, but it is willing to lend to the government.