This is a really useful thing to keep in mind because even if you aren't directly bound by a requirement to follow the NIST standards, being able to point your policy people at that is handy if you can shift the conversation to “bring our policy in line with NIST” where there's a question about whether they'll later look bad for _not_ having done so. Typically these conversations are driven by risk aversion and things like federal standards help balance that perspective.