Not everyone knows C. A large percentage (maybe even the majority) of programmers who graduate from Java schools don't know C very well at all. For them, "it works just like C" is an insufficient explanation.
As someone who started in Asm, I think pass-by-value/pass-by-reference are also intuitive there in the true "understood without needing any explanation" sense, since basically everything you'd pass to a procedure is a value of some sort, and it only depends on whether you are to interpret that value as a memory address.
In my intro-to-java-class, indirection was one of the first things we learnt when we learnt about objects: variables hold a reference to an object, not the object itself. I don't understand why pointers are somehow a great insight that is exclusive to lower-level programmers.
And if a java person ended up trying to make a method that swaps two primitive values, they'd have to learn about the distinction between passing a primitive value into a method as opposed to passing a reference to an object.
>I don't understand why pointers are somehow a great insight that is exclusive to lower-level programmers.
They're not. You don't need to be a lower level programmer to understand pointers, but it helps immensely if you know at least a bit of a low level language.
When you're getting into details like call-by-reference vs call-by-value, it really helps to have a mental model what the computer is doing. You don't need to be an assembly programmer, but it does help if you spend a little time studying assembly language.
The example given would be, in Python,
def double(x):
x *= 2
a = [4]
double(a[0])
[1] http://www.cs.sfu.ca/~cameron/Teaching/383/PassByName.html