Why PIA cannot make full use of it's 747s outside of hajj

I was recently having an argument with an associate who used to be an aircraft mechanic. He was very critical of Pakistan International Airlines (PIA) decision to ground their 747s claiming that they were loosing more money by parking them and not flying them.

I found his reasoning to be flawed. Firstly for an airline to ground it's fully functioning planes is mostly due to lack of passengers for that airline. To use a fully functioning 747-300 with few passengers is costly. The airline could loose more profits than gain especially due to the 747 using plenty of fuel as well as maintainance costs.

Another argument thrown was that the airline will be paying heavily for parking fees. This isn't correct. PIA being the national airline of Pakistan is owned by the government has it's main hubs at Pakistan's international airports.
This simply means the airline is using government property so it would not have to be paying parking fees.

Then came his argument that PIA should get more passengers in order to be able to use it's 747s.
What people don't know is that PIA looses most of it's international passengers to airliners in the Gulf region which offer lower fares and better timings.

It's important for people to understand the circumstances before being critical of airlines or calling for the use of certain planes which are fit to serve different markets depending on what model they are.