I worked for SDC during the latter part of that timeframe as one of the support reps. A large number of us complained to management about the detection software; it was very old at that point and couldn't detect some newer malware, and the message it put up for not finding anything was essentially "you should probably have the machine checked out because there's a lot of newer stuff on a day to day basis"-- basically a full-on scare tactic even if true.
Management also treated PUPs (potentially interested programs) as full infections, with the general idea that if someone knew enough about the machine to install those, they wouldn't come to us for help. While true, it felt to me that they really felt the need to pad the results as much as possible to justify the service.
That said, we did find quite a bit of junkware, malware, spyware, and legitimately concerning pups on a regular basis. If they'd listened to us and updated the software sooner, things might've gone better for them. In the end they made the staff redundant by moving service overseas, and I jumped ship as soon as I saw the end coming.