It is the system that allows you to play the system for 20 years. If the process were more clear cut and less slow then I'd agree with you but after some reasonable period of time (say 5 years) has passed and someone has proven to be a productive member of society it is in everybody's interest to maintain the status quo.
People have come to the US in their 40's and have died of old age waiting for their paperwork in cases where everything went A-ok (ditto for Canada), it's no surprise that the negative side is just as slow.
Case not finished in 5 years? Here is your passport.
It's typically not the people that go through this mill that control the speed with which it turns but the government side.
Note that it took more than 4 years before they even had their first hearing.