I guess the volume of discussion can be attributable to that there are enough Haskellers and enough non-Haskellers.

Haskellers read some texts and got used to the idea of type manipulations. They know, for example, there is a type "Void" which doesn't contain any values - that is, by definition no object has this type - and therefore any function which has this type of argument can't be invoked. Because to invoke the function, it has to be passed a value of the given type, and there aren't any.

Haskellers got used to the idea that if we have function from type a to the same type a, and there are absolutely no restriction on what the type a is, then it should be identity function - they just sat on this idea, pondered it for some time and got to this conclusion. For non-Haskellers it's not clear - and even the idea that types can restrict code so tightly as to make code unique (up to isomorphisms) can be novel to them.

Does it make a bigger cognitive load? Probably not for those who got used to type properties like this. Is it hard for non-Haskellers to see this feature and try to use it? Well, many Haskellers passed through this stage, so it ought to be doable. Most importantly, can they agree on this?..