The sole is 70% fiberglass, not full carbon, according to the bontrager website, and they also say it rates 10/14 on their stiffness scale.
A non-carbon sole is always going to be somewhat flexy compared to a real carbon sole. I can easily flex a fiberglass sole with my hands. Can't get a carbon sole to budge.
For the MSRP on those, I think you could get a better shoe...