I definitely agree with you. I've never been a fan of yuri manga, but I read a shoujo-ai manga and it was okay so I thought I'd try and read something a little more adult-like (haha the wrong word to use) and I liked the idea of a story about first love... However, this manga did nothing for me. I totally relate to your comment
Couldn't have said it better myself (although I attempted to) :D
I'm a woman too... And I thought this was extremelly erotic. I mean, it didin't turn me on, but I can't deny it was sexy.
As a Yaoi fan, I was always baffled why THIS manga constantly showed up in my suggestions. So after months of ignoring it I decided to read this as my first Yuri manga. And after reading this story I've come to the conclusion that either I chose a bad example as a "starter" Yuri manga, or I'm genuinely not into Yuri. I didn't really FEEL anything while I was reading it. Was it a bad story? Not really. It was extremely hyper-sexualized like most "dirty" manga are. And was the art bad? No. It was well drawn!
I'm a straight female. I enjoy seeing men in sexual situations, whether it's with a female or another man. Sadly, I got no enjoyment from watching two women going at it. To be clear: there's absolutely NOTHING wrong if you like Yuri manga over Yaoi, or the other way around. Everyone has their own preference!