Yep, they say the pointy helmets only work properly when you are facing straight ahead with your head at the correct angle.....and never move. Which is of course not realistic for road cycling and especially a TTT.
Even more so, the added weight is a strain on the neck which is a waste of watts.
It helps that many of the modern 'aero' helmets are as wind tunnel aero as the sperm helmets are. The Giro Air Attack is a good example.