I think the suggestion is that Robert's Rules have actually the result of a bunch of previously tweaking, have been tested, and are shown to be safe to implement.
On the other hand, many other decision making procedures (such as many alternatives to the U.S. first-past-the-post voting schemes for elections) might sound good in theory, but in practice could fail utterly.
Surely this is more about parliamentary process which is somewhat independent of the voting scheme? How do you even measure the success of a voting scheme? Most modern democracies use a form of proportional representation these days. This is particularly true in Europe, where most countries also score higher than the US on the Democracy Index: https://en.m.wikipedia.org/wiki/Democracy_Index .
Even in the US, non-FPTP voting is starting to happen here and there. San Fran's mayoral elections used a ranked choice system if I'm not mistaken.
Item 14 is pretty interesting too. "Is the legislature the supreme political body, with a clear supremacy over other branches of government?" That's probably a no for the US, but who knows. The "experts" who make the determination are not revealed, so the whole index is really based on trusting what The Economist says.
Item 18, "Do special economic, religious or other powerful domestic groups exercise significant political power, parallel to democratic institutions?". I can't imagine how that can be fairly scored: the only realistic possibility is that the "experts" vote on how much they like the interest groups in this or that country.
There are lots of items like that. Even if they make sense for a democracy index, you can easily see how different people might give completely different answers.
In item 40, "Alternatively, % of people who think that punishing criminals is an essential characteristic of democracy", where you get the full score if that is over 80%. Wouldn't most people say that punishing criminals is an essential function of _any_ government, not having anything to do with democracy in particular? On the other hand, many dislike the very notion of punishment. In the US, this waxes and wanes; does the country really become more democratic during the "tough on crime" phases of the cycle? The index seems to say so!
All good points. As discussed in that doc it is very tough to define and measure democracy, and as with many fields of knowledge there comes a point at which the laymen have to trust the experts.
Regarding item 10, the UK has FPTP but political parties other than the biggest two are nevertheless able to wield significant political power. Even if that weren't the case I wouldn't call it a tautology. Rather I'd say that the tendency of FPTP to lead to a two-party systems is one of its democratic flaws.
Regarding item 40, yes: most people would say that preventing crime is an essential function of government, but many countries value rehabilitation over punishment. You're correct though that there's some ambiguity about the meaning of "punishment". Without delving into the World Values Survey itself it's hard to say much more.
If UK has FPTP, why isn't it a two-party system? I thought Duverger's Law means that its third party would die out to be more like the Green or Libertarian party in the US.
I can't put my finger on it but there's something about US culture that leads to sharp polarisation in social, racial, religious and political spheres.
That first line could mean several different things. Are you claiming that the excessive power of fringe elements in the EU is why the UK decided to leave?
From a global perspective, the UK and US are currently undergoing existential crises - arguably due to people feeling politically underrepresented - whilst many countries with a strong PR such as Finland or Switzerland seem to be functioning better.
On the other hand, many other decision making procedures (such as many alternatives to the U.S. first-past-the-post voting schemes for elections) might sound good in theory, but in practice could fail utterly.