It is good for what a regular math degree is good for. Going on in math, getting jobs that require a university degree, and going on to become something like a lawyer.
Understanding fields in which there are historical applications of math is not required to understand math perfectly well. Furthermore (depending on your interests) it is possible to find all sorts of applications of math outside of the sciences. A few non-science areas where a math background would be good include social sciences (particularly if your math had a focus on statistics), law school, and philosophy.
You may have had issues with other things about this person. But the degree described seems quite reasonable to me. At least from my perspective as someone with a graduate-level math education.
Cheers,
Ben