Why are urban fantasy covers so bad?

I read a little bit of urban fantasy. I've liked what I've read. I want to read more. Why haven't I? Because I can't carry these books around in public. Urban fantasy covers seem to always have half-naked women sometimes sporting tramp stamps. I like to take my books to work. Sometimes I steal a few minutes to read on my lunch break. I work for Girl Scouts. There are kids at my office and I consider myself a role model.

Let's look at some of the covers:

I've been told this book is good and that I should read it.

I've also been told by readers they have no clue why the cover looks like this.

I plan to read it on Kindle because I won't carry this around.

I see people reading this book online all the time. This author seems very popular.

The covers always seem to feature half-naked women.

I'm not saying anything bad about the book. But I wouldn't carry this in public.

Just read this book. And its got it's moments of being inappropriate.

But why does the cover need to be?

(And the character never actually ya know, does it during the book.

Also, any occasion she has to be naked she's not blonde)

IMPROVED DARKFEVER COVER

Good UF Covers (with clothing yay)

I love this series.

Look how pretty the new cover is. Lovely.

Apparently boys get to wear clothing.

I think part of what confuses me is that I constantly hear about how most readers are women and women tend (TEND, not saying always, nothing is always) to read both male/female POV & men tend to read only male POV. So who are these books advertising to? Why do they look like this. If anyone has an honest answer I'd love to hear it. I know they say "don't judge a book by it's cover" but I was a graphic designer and I love book covers. Also, I don't want a book that I can't read in public and proudly suggest to other friends. I love recommending books but I don't want to have to explain-away a bad cover. I hate saying "I know the cover is horrid but the book is really great."