It temporarily relieves discomfort, but it certainly doesn't address the underlying issues. Unless those are resolved, the individual can become dependent on the drug (whatever it is) to keep functionality.
The biggest issue is: what if the underlying problem is unfixable? For example, chronic pain. What is the best solution for those cases?
Marijuana may not be an ideal solution, but it is one of the better, if not the best, solution we currently have for certain cases.
But I agree that a lot more research is needed. It was the government that prevented that research for decades... Can we let the market work?