This is quite a lot more saddle to bar drop than I have on my own bike which is much closer to the 8 cm saddle to bar drop of Lance Armstrong when he was still racing.
After doing a little more research on the internet I found the atricle I will post below on The Inner Ring website which I found very interesting which includes even more links within the article about bike fit.
The interesting thing I think is that while it seems that saddle to bar drop is getting bigger to compensate riders tend to set their saddles further forward on the rails which suggests they are no more flexible than they were 20 years ago. As Gerard Vroomen founder of Cervélo suggests a riders flexiblitiy is fairly consistent and to get lower and further forward they are just rotatating around their pelvis. In fact the interesting thing to note myself is how low and aerodynamic riders like Eddy Mercxk were with a much smaller saddle to bar drop as shown in the video below.
After reading all the information and looking at different videos I can also see why riders would be interested in following the latest trend set by the likes of Alejandro Valverde who is World Champion after all.