I'm guessing that most people who visits a website called "My browser fingerprint" with a domain of "amiunique.org" has at least a fleeting interest in privacy

I'm guessing that most people who visits a website called "My browser fingerprint" with a domain of "amiunique.org" has at least a fleeting interest in privacy and making choices around that. And that group is most likely biased to using Firefox instead of Google Chrome, at least compared to a general section of the population.