Why doesn't it make sense ?? The ONLY thing that will make a difference when it comes to negative marks on your reports is TIME. As long as the collection, the charge-off, the lates, remain on your report, even if you pay it off, its STILL a negative tradeline and it will continue to tank your scores until it drops off at the 7-1/2 year mark. A paid charge-off, which is what it would be, really only matters to a lender, but to FICO it is STILL a NEGATIVE and is calculated as such.
So, paying off really old debts doesn't do you ANY good score-wise.. its only good for you if you're looking to buy a house and the lender wants to see them paid.