The whole point being that people know the history of the vehicle. If you get the advisories repaired, then you've got nothing to worry about, as you'll be able to prove they've been done.
The main reason for advisories being recorded, was to prevent people from doing the minimum amount of work to a vehicle to get it through an mot, with the sole aim of selling it afterwards. Before, provided the vehicle got an mot, they could chuck the advisory notice in the bin, and any prosprective buyers would be unaware, of potentially serious advisories. Now it's marked on the MOT certificate that an advisory notice was issued, so any buyers know that, and they can check to see if any remedial action has been taken.
Also, it's a way of testing stations to prove that they've noticed something questionable (VOSA prefer testers to pass and advice on such things). An example might be a corroded brake pipe, where it might not appear to be rusted enough to fail the test, but should the pipe fail the day/week/month after the test, the garage can proof they noticed it, and VOSA won't take the issue any further. If they didn't advise about the pipe, they would be facing loosing their testing station license. By having it recorded on the computer at the time of the test, the system is tamper proof, unlike the previous paper system.
He can't be very good with the computer then. Takes the testers at work under 5 minutes to complete one test, and log on the next test.