Size 4 is perfect?

I'll admit it, I LOVED the Sweet Valley High books. I can still tell you which one was my favorite (the one where the parents go out of town and good girl Elizabeth lets her boyfriend sleep over), and I'm pretty sure I tore through almost all 100+ of those books. I was even a little excited that my younger sister would get a chance to read all of the soon to-be-reissued books, until I saw an article that included a letter sent by the PR group in charge of the re-launch. The letter includes a side by side comparison of the old books and some of the new 'updates.' While I could care less that the twins now share a red Jeep (instead of the old Fiat), I was pretty upset when I realized that one of the highlighted changes has to do with their weight! In the original series the girls were a 'perfect size 6,' and now in the new books they are listed as a 'perfect size 4.'
I'm not sure I would have noticed the change, except that the PR people went out of their way to highlight this as an important aspect of the revamped books. In addition to the scary message they're sending about the value of shrinking waistlines, I wonder who decided that this was worth noting to book sellers. You would think Elizabeth's foray into digital media would be way more indicative of how they've updated the book to appeal to a new generation of readers. Blogging as both a word and activity would have been entirely missing from the original series, and would date the new series way more than clothing size. I think it says something (something scary!) that some editor decided that size 6 was no longer the 'perfect' size and every book title and publicity campaign should highlight how the girls are now smaller. From what I remember the twins were also described as being medium to tall--maybe 5'6'' or 5'7'' --which would put their new size 4 frames at almost model proportions. While there is nothing wrong with being tall-ish or slender, I think they're sending a pretty bad message. Even for idealized blue-eyed blonde California girls, why is a size 6 (which is still WAY below the average clothing size for a woman) too big?