By your logic, all classical computers are measuring voltages and calling them bits.

A computer is just an experiment, right?

All of the awesome things we build with computers are just propaganda.

I think "propaganda" is too harsh, more like "spin". This is apparently a fine achievement of quantum optics that will hopefully be applicable to quantum computing. But it is being directly billed as a quantum computer itself, which is a stretch.

A classical computer is more than an experiment. The "just" part of that statement is what matters. Computer implies some degree of generalizability in computing things. If it can only compute one thing, it's at the trivial extreme and would be more logically described in terms of that single things it does. For example a beamsplitter that divides power in half. We call it a beamsplitter, not a classical computer that calculates 1/2 input power.

Perhaps its a bad article, but I can't see the value of solving the boson sampling problem by sampling bosons having any application in general computing.

It probably does not, though there are some proposals (such as generating certified random bits I think). But that is not relevant to the discussion here. A computational algorithm does not have to be useful generally, for it to prove a result about complexity classes.

It depends how general you mean, I reckon. I don't know enough about physics to know how important boson sampling is, but simulating other systems in particle physics is already one of the big-ticket uses of supercomputers today.

Given a set of inputs, it computed the result.

Also, did you read to the end? They directly address the issue.

I'd tend to agree the latter but not the propaganda since the Westerns indeed admit this achievement. Yeah, what is the advantage if not turing complete anyway?

A computation model doesn't have to be Turing complete to be useful in practice. Consider a language where all programs must halt - all loops must be bounded, and recursion is not allowed - you can still solve a lot of problems with a language like this, but you cannot say, run Brainfuck, as such a language is not Turing complete.

What's the advantage of the abacus or the Enigma machine? Or any of the many Turing-incomplete machines that were built before fully general computers in the 1940s-50s.

This talk might enlighten you https://www.youtube.com/watch?v=njwQgz63rIs