"Children's" Books

Okay, I was told I needed to post, and I have no idea what to post about, so I'm going to rant about so-called "children's" books. 
As anyone who knows me can tell you, I'm a loser that goes over to the children's section as soon as I walk in the library (note, I'm a loser, not a predator).  To cement my loser status, I have officially read every single hardbound chapter book in the children's section at my public library. 
As I've spent the past years doing this, I've stumbled across some stuff that has seriously disturbed me.  For example, the book with several pornographic drawings in it.  (Not as bad as the Men are From Mars incident, but dang close). 
I also distinctly remember reading a book one time about a girl kissing a boy and her friend asked her some questions that made no sense to me at the time, but make a scary amount of sense now.
And periods.  Seriously?  Why in the world does everyone write about their period?  It's disgusting!  I still get embarrassed if a pad commercial comes on and my dad is in the same room, yet a good 30% of the books I've read talk about it.  Do I really want to explain to my 3rd grader what a period is?  No.
(On a side note, I had that wonderful talk with my mom in a crowded Disney Land bathroom when I kept demanding a "treat" from the machine.  She finally explained, in an effort to get me to shut up, and I was horrified.  I still am).
So why do authors, adult authors, I might add, throw in stuff that's completely inappropriate for children to read?  I just don't get it.  I can't even begin to count the number of books I've read that have mentioned puberty, specifically a girl "developing" in the upper region.
Freaking sick, nasty people.  Let's just all go back to Sesame Street.  Oscar the Grouch doesn't have boobs.