Yes, that range looked odd to me at first glance. But your explanation made me realize that I actually use it all over the place. Except on a 1-5 scale. Starting with good enough at 3 (or 0 in this case):

1 = WTF?

2 = Needs Improvement

3 = Good Enough

4 = Better than Good Enough

5 = Almost Perfect

Daniel Kahneman recommends a scale like this for evaluating job candidates across core competencies. It's a surprisingly powerful little heuristic.

The [-2,2] scale made immediate sense to me because it's zero-indexed:

-2 = WTF

-1 = Needs Improvement

0 = Good enough

1 = Better than Good Enough

2 = Almost Perfect

It's even intuitive, since anything above zero is 'above and beyond' and anything below zero isn't good enough yet.

The system makes sense but it feels like there is probably a more intuitive easy to express those than with numbers. Naming is hard, of course, but off the top of my head maybe something like

-1: Changes Requested

-2: Declined

1: Approved

2: Accepted

Why would that matter? This is for developers, not English majors.

I didn't down vote you, and your question deserves a serious reply because the same principle is broadly useful.

Communication is hard. People actively in the team probably have the context to understand the differences, but that implied context is what tribal knowledge is made of.

OP indicated that there were non-trivial "non-linear" differences going from 1 to 2 and -1 to -2. The use of numbers implies a relationship that doesn't really exist. The use of accurate language makes the actual meaning immediately obvious without the need for implied context. For example, I had no idea that only privileged devs could give 2s. "Accepted" and "Declined" do imply a finality that more accurately mirrors the intended usage.

This may seem overly analytical for something that is easy to just explain, but this kind of thing build up in layers.

Exactly this. It's not as if two +1s equals a +2 (which one night intuitively think based on the nomenclature).