Comment I posted here : Artima - To type or not to type
But let's get back to the original assertion which could be phrased : "People argue about types because different people need different things. And they're tacitly talking about the kind of people they are and the kind of projects they work on."
Now, this is obviously true. In a sense these arguments are a kind of politics. Compare : "some people like government to tax economic activity and spend the money on welfare and protecting worker's rights, and some people don't".
When people argue about politics, they are often asserting the kind of person they are, and the kind of project they are working on (ie. the economic "class" they belong to.)
But the real reason people argue this, *isn't* because they like talking about themsleves. The reason is that if they DON'T argue, then there's an increased danger that the other world-view will seize control of the state and impose their preferences it.
In the same way, we argue about types because people are always trying to foist projects and the use of languages which accord to the opposite world view on us. If we don't try to defend our view, these people will sell languages based on the opposite principles to our employers, and our educators and our customers, and we will be forced to live with them.