You're going to listen and say, "How is it that this girl got so far in the business?", but I urge you to keep an open mind. After you listen to the atrociousness of the first video, go to the second and have a listen, especially from about 1:00 onward.
This girl has some pipes! Or at least had them. It's hard to tell what her current vocal state really is with the so-called songs she now records being so unchallenging. Plus, when your fans care more about how you look and dance than how sound, the Brit has no reason to push herself.
I'm not a fan of Britney, especially of her music, and I don't want to be seen as an apologist for her. I don't believe for a single moment that she'll ever produce any kind of music that will last beyond a year, but I do think it's a real shame when someone lets any real talent they have waste away.
Don't forget to check out my Music 3.0 blog for tips and tricks on navigating the music business.