A protagonist is different from a hero in the way that they have no real heroic attributes (think Avengers) but they are the main character that you are supposed to root and/or care about. For instance, Mad Men has a plethora of protagonists but absolutely none of them are heroes. You still want them to succeed but in terms of role model material, they don’t even appear on the list.
The ones on this list are meant to be the main draw of their respective series or at the very least, be someone you want to see accomplish their goals. Yet none of them inspire the feelings they are meant to. Instead, viewers usually fast forward through their scenes or just ignore the character all together. Their main purpose seems to be introducing the other characters and storylines but then after that job is done, they lose all sense of importance. Viewers tend get more satisfaction seeing them told off or a character that stands up to them. Minor characters steal the spotlight, making it obvious that the show no longer depends on these particular protagonists to keep the audience coming back for more. In some cases, their death scene is the best thing that ever happened in the show; other cases highlight how dull these females really are.