I don't see how scientists or staticians would be unable to understand a basic knowledge like zero-based indexing. In fact, zero-based indexing already is widely used in basic areas such as series and sequences. Why are freshmen quite capable of understanding such a fundamental convention but somehow seasoned scientists and statitians are not?
Of course they can. In fact, they tend to have a complex relationship with indexing which is why Julia supports such a rich indexing language.
But the default the Julia team chose was the natural, mathematical default rather than the natural memory addressing default. Which, given what they were trying to achieve, was entirely sensible.
And, on a side note, just because something is physically possible, it doesn't follow that it's the most sensible choice. Otherwise language development would have stopped at the first Turing complete language.
What the Julia team is attempting to do is make the transition for their target audience as seamless as possible. This can be seen in their indexing language but also in their choice of dispatch, their type conversion architecture etc. A great deal of thought goes into these decisions (you can see it in their issue/RFC trackers). "A CS freshman could work it out" doesn't even come close.
And science has lots of 1- based indexing: Matlab, Fortran, R, most math...
I'll tell you: it's very, very, very easy. And when a language makes things easy, people tend to like it (that's one of the reasons people like Python after all).
And it's a good attitude for the Julia people to have. Their target audience is not just (or even mainly) full time developers. They're targeting scientists, statisticians etc. As such, it makes sense for Julia to use conventions that are appropriate to their audience. This pervades the whole of Julia, not just indexing although the latter is exceptionally rich for this reason.
> Programmers just like it
That's a reason for having 0-based indexing but not an especially good one. And for Python it was an arbitrary decision. That's not to say that 0-based indexing is necessarily an arbitrary decision, it wasn't for C, for example, but it often is.