Can we stop making this comparison? At best it is naive at worst you're purposefully misrepresenting the argument.
When people say "social credit score" they distinctly mean something different than "credit score" (you may get this hint by the extra word, "social").
A social credit system not only includes your finances, but as well as much about your behavior. Such as "do you buy cigarettes? How often?" FICO doesn't care about this, they just care about if you're likely to pay back debt (based on your track record of doing exactly that). FICO doesn't care if you're Muslim, black, white, Christian, etc. But a social credit system DOES.
Rather than putting a score on your likelihood of paying back debt, a social credit score scores you on how "good of a citizen" you are. Not just legally, but morally. And that's the danger. Morals shift and vary a lot (more so in the US than most countries). There's a general belief in most first world countries that your skin color, religion, gender, etc should not play a role in how the government of businesses treat you. Social credit systems (even if they don't explicitly add those factors: ie implicit) will use these factors to rate you.