It is just an older field with more established "traditions" and big names that reinforce themselves over time. Regardless, I don't think it is relevant. By number, life science research is only behind the military in funding. And by utility, show me one person who does not depend on any kind of healthcare or medicine and I will show you ten people who never used machine learning products (easier to find than you think when we get out of the western hemisphere). It is banal to claim ML has more utility. It sure can make more money, but the impact on a personal level isn't comparable. Society can still function without AI but take away healthcare and you will see it goes to shit real fast.
I find this ironic, given that my degrees are in engineering and now I am doing life science...
There is nothing wrong with people getting a degree in what they like and then find a job that make them happy. I do not categorize or draw conclusions based on the degree. I care more about what the person can do. Most of the time a CS graduate isn't that much different from a bioinformatics graduate. And a biomedical student isn't that different from an engineering student when we are trying to build that bioreactor...