However it is called, there are many reasons for why it is so bad, but they all boil to one point: it's asking voters for information they do not have while ignoring the human realities of the vote. As we code monkeys say: GIGO.

99% of humanity doesn't have a 'Score' for politicians* , but the reality of the vote is that whatever choice the voter has, the voter can push effectively by giving min/max scores - or at least is very likely to think it can be helpful, and feel guilty when they don't do it - imagine losing an election because you merely gave your preferred candidate an 8!

A Range Voting election where everyone gives min/max scores de facto may look mathematically identical to Approval Voting, but it is far worse in reality.

That's because voters will then convince themselves their choice is deserved - their politician is a 10 and the other is a 0, an enemy. The problem in other words is that voters will mostly not partially abstain, but be pushed into a false polarization beyond what is useful for society. Psychology, not math.

There are other points, but this message is long enough. TL;DR: "Score" voting is the triumph of mathematically optimized voting methods that ignores too many human considerations.

But look, I am willing to go half way: Approval voting is a perfectly good method and I can accept Borda. Both are strictly better than the current method even according to the weird measurement "The Center for Range Voting" uses. Approval can even be seen as a (sane) version of RV, so there's no reason at all for the center to object.

* Oh, and the 1% who actually has a score? That's almost worse, because these scores are nearly always the compilation of single issue organizations which tend towards the extremes and never look at circumstances.