Marrtin's observations and the 2nd half of Spamdalot's are close to the mark to me. The 'befores' that are being posted are for the most part the product of one or two people's creativity: the "afters" are the product of accountants, marketers, execs and focus groups. After all, these companies just want to sell as many boxes of frosted flakes as possible. Naturally they're going to test package designs and choose the one that offends or jars the fewest people. The result is not 'bad' design-- it's 'blah' design. The focus shifts away from what people find attractive-- since people's likes are as pointed and individual as people-- instead to what's least objectionable. Kinda like padded cells.

Unfortunately, it's simple mass-market economics. Which is why I like niche markets better.
Take for example Spamdalot's observation of the bunny's "beady eyes". This he cites as "inhuman". what I think he means is simply that he doesn't like them so much. I like them, myself. Think of Watterson's Calvin. Spamdalot writes favorably of Struzan. I can't stand Struzan's work, personally. (I'm not saying Spamdalot's wrong, I'm simply pointing out differences in our opinions.)
So how the hell are you going to sell a box of cornflakes to both me and spamdalot? Well, if you put Struzan's art on the cover, you might hook Spamdalot. But you've just ensured that I will never buy your cornflakes, nor will I purchase any other of your products, ever ever again. (yeah, I dislike his work that much.

) I might even go out of my way to see that others boycott your product as well. But odds are if you put something on the box I'm wild and crazy for, Spamdalot or someone else might not like it.
So what do you do? You find the image that the most people can tolerate. They probably won't love it but at least very few people will hate it.
(my thanks to Spamdalot for letting me pick on him as an example. No offense intended.)