Cannister filters, why so bads?

Every one says that I should not use the pleated paper canister filter that is part of my 75 salt water aquarium set up that has been in my attic for 25 years. That, along with the trickler filter and bio balls, was state of the art in the 80's.



What is the problem with using such a filter if, and I emphasize if I change the filter weekly? I have two extra cartridges for convenient changes.