So what do you suggest? Ignoring race altogether would just result in blanket statements applying to the entire species. The goal in medicine is to cater treatment as best to an individual as possible. Basing treatment plans based on our genomes would be ideal, however it's not really feasible at this point in time (though that will likely rapidly change in the coming years)
1) It's still expensive, especially if you want results ASAP
2) Even though we know many conditions are hereditary, identifying which genes cause those condition is rather tough. Even for something as simple as curly/straight hair, we haven't figured out how to identify that with just a genome with 100% accuracy.
So in the absence of genetic testing, next best thing is family history. However, family history has its limits in that records are far from perfect, we only have access to a generation or two prior to our own, and sometimes due to the genetic lottery, you'll be the first in your family's recent history to exhibit some issues.
So when you can't get the information you need from genetic testing or family history, the next best option is your race. No it's not perfect, and yes, now that mixed race couples are more common than in the past, it will likely become less useful within a couple generations. Hopefully by then genetic tests will be sophisticated enough and cheap enough for that to no longer be an issue.