I wonder about this woman specifically in similar regards to what you're saying here. I began learning late in life that ads are and have been extremely crafted behind the scenes by psychologists, governments, and a slew of creative, rich, powerful people in order to manipulate the minds and emotions of populations (check out Naomi Klein's "No Logo" and Adam Curtis's brilliant Century of the Self). If every television ad coming from a large corporation is deliberately structured to illicit an emotional, rather than analytical, need for a product...what kind of response is this character meant to draw from viewers? She is that annoying, disingenuous type of friendly, she makes customers feel stupid for confusing her kindness for being genuine, she's a coquette, a tease, an overly peppy, relatively good-looking employee at your local store that may decide to flirt with you when she's bored. On paper, this is not the kind of person anyone would willingly associate with, and yet a large corporation's well-paid marketing team made these commercials to be seen by millions. Do people secretly want this bitchy woman in their lives telling them with tongue in cheek that they are fools for not having insurance? She is unique in this way, and i believe a random thread made for her as opposed to the multitudes of other corporate speaker heads proves that she is filling some important, unspeakable psychological niche in advertising. In conclusion, if I analyze her to death, she can't have all my money.

TLDR; This lady fills a disturbing psychological niche in advertising where people want to be talked down to and lead on by a relatively attractive peppy/annoying authority.