Is the "$\pi$ is wrong"-movement serious or a joke? [closed]

Is the "$\pi$ is wrong"-movement serious or is it to be taken as a joke?

https://www.tauday.com/tau-manifesto

If serious, what are they hoping to achieve? Throw out every book with $\pi$ in it and make up new ones with $\tau$?

These people have a point. But they must know that their quest is doomed to failure. It's like proposing that humanity switches from base-10 to base-12 counting, because it's more logical. Or changing the sign of the electron's charge to $+$. Or using proportional representation to choose our elected leaders. Or switching to metric worldwide. Or...the list is endless.

Think of them as hobbyists rather than crusaders.

$\pi$ is actually a little bit better than $\tau$ according to The Pi Manifesto.

If people can't change the sign of electron, they won't change the quantity for $\pi$ either.

I'm pretty sure that some people seriously believe expressing things in terms of $\tau$ is a more useful convention than in terms of $2 \pi$.

Changing the convention, one must get people to adopt the new convention. If it's useful enough, then over time it will become known enough that its adherents can use it without explanation. If it's that much better, it will eventually replace the old convention.

Either outcome would be a desirable goal for those who believe such a thing.