Yes, perhaps Pamela was more pointless than ruined; however, after initially appearing in season 3 as just another assistant to Richard—a brunette this time—Sarah Douglas suddenly made it into the opening credits in season 4. Real effort was actually put into developing Pamela, notably through her fling with Greg and her role as a confidante to Lorraine. It is all the more surprising, then, that the character was simply dropped. To this day, I still haven't quite understood why Pamela suddenly felt the urge to blow up Richard's house. While the fact that she needed a new face afterward made a certain amount of sense, why did she have to keep her old hairstyle instead of getting a complete makeover?
I have to admit, Frank wasn't even on my radar when it came to the most ruined character. I was thinking more of Melissa and Julia—and maybe Chase (because of his behavior in season 6). For anyone who liked Julia the way she was at the start, she might have been ruined by the season 2 finale; after that, her storyline was simply overused. Taking a break from her in season 6 was a good idea, but letting her rot away completely in a convent wasn't what I wanted either. As for Melissa, she headed in a direction during her final seasons that I didn't like at all. Nevertheless, it was good that she remained part of the show (at that time) and wasn't written out so unceremoniously—as was the case with Terry, but then, it happened to her after all. I’d always considered Melissa a pretty strong and smart character, but in the later seasons, she was written solely to suit the plot at hand, and I’m not sure if her original strength could have been restored—even if the writers had wanted to.