Proportional representation is undemocratic, and based on a fundamental misunderstanding of what democracy is.
The best way to measure how democratic a country is, is to measure how much support its policies have among the public. The approval rating.
This directly measures whether voters think the government is representing their interests, and is a better measure than any feature of the electoral system itself, like seats, or vote share.
The myth propagated by PR ninnies is that somehow the number of seats held by each party is a good measure of how well the government represents the public.
There are several problems with that.
First, PR causes parties to focus on a narrow niche constituency, rather than being inclusive. This results in less effort to bridge gaps and generate broad consensus. People are better represented by a broad consensus than they are by narrow issue parties. Call it holistic politics.
Second, PR systems reduce the connection between an elected official and the public. You no longer have a person representing you. You have a party, with no clear individual watching out for your interests. In mixed systems, the power of your local representative is watered down.
Third, FPTP systems magnify voter intention. Small shifts in voting result in big shifts in the seats won. This makes the public more important, raising the importance of voter opinion in the political system versus lobbyists.
For all these reasons FPTP is more likely to produce a moderate government that appeals to the largest number of voters, far more appeal than the number of voters who voted for it.