Fixed Time Trial Bikes

It's probably true that many people who haven't been to a wind tunnel or done extensive field testing are getting no more benefit from long-tailed helmets than they would get from shaving their heads

Assuming this is true (which I like to do with your statements), it's still foolish to engage in competitive cycling without a helmet. An aero helmet* is going to be considerably more aero than a normal road helmet, with or without windtunnel tuning.

*Not necessarily the pointy type but also the smooth round ones.