If you have to stay motionless 10 to 30km from shore in order to launch an amphibious assault, how likely would you escape from harm's way? Even if you have escorts from DDGs and FFGs providing defensive shield, a few lucky short range missiles from shore defence might still get through.
The top bow of the ship is the least fatal to its operation, using non-slanted large flat surface at the bow presenting larger radar return to attract in coming missiles, so that they would not hit the super structure and other vital parts may be worth the damage sustained.
The ship can't be stealth at 10 to 30 km range, so a bright radar spot at the least fatal part of the ship can be a defence of ultimate last resort. Of course, hopefully, the anti-missile missiles, ECM, Chaff decoys will work so that this scenario could be avoided. May be they fortified the flat surface with something similar to Chobham armour? Notice the flat surface covers the front as well as the two side of the top bow.
Just my 2 cents. Constructive argument are welcome.