They can show the consumer, “Hey, look at our capabilities! We are putting these same tools and knowledge into our bikes!”.
It also shows that:
a) there will never cease to be amazingly counter-intuitive results from the wind tunnel
b) not everything can be easily replaced by computer modelling. Try a modelling a variety of leg hair in STAR CC+, etc. I bet it’s not fun.
These are good points. Also, your the last point could easily have the words “computer modeling” replaced by “wind tunnel”. The goal of all of this is to find free real-world speed, and the computer and wind tunnel are just simplistic models of the real world.
In Michael Hutchinson’s book Faster, Chris Boardman talks about how computer modeling enabled British Cycling to calculate esoteric stuff and just let the computer sit there and crunch for hours overnight to find marginal gains in areas that no one would ever think of looking (shape of the front fork, for instance). Then they would actually test what the computer suggested with a real rider on a real bike. More often than not, the computer’s suggestions did not ending up making any significant difference in the real world. But sometimes it did. And it was a lot easier to have a computer point them in the right direction than just randomly guess and try changing everything one piece at a time.
The wind tunnel is the same thing - results in the wind tunnel often do not match up with what you get in the real world. Boardman talked about how surrounding trees / foliage and buildings would often complicate things, especially when you’re talking about things like dirty air caused by rotating wheels and churning legs.
A lot of wheel companies, I suspect, test their wheels in the wind tunnel by themselves (not on a real bike with a real rider pedaling). Which doesn’t really have any applicability to how they will be used in real life. Same way a lot of tire companies test their tires on a steel drum (not on a real bike with a real rider pedaling).
Anyways I’m not trying to argumentative or simply trying to be a contrarian here. I’m by no means a professional aerodynamicist, I’m just interested in this topic and try to read as much as I can about it. That’s why I’d like to hear what Mark and Chris have to say about this.