I see the purpose of BSc or MSc is to learn to be able to make an analysis of a given subject (related to your particular field) and write a structured and coherent report of it. To do this you need to learn how to use the tools of analysis particular to your field (e.g. calculus, physics equations, balance sheet, schools of thought in philosophy etc.). So when you are done with the school and have BSc or MSc if somebody gives you data and a research question you can apply the tools and write a report/essay.
To be a researcher you need to learn how to make/enhance those tools & need to see the problems and limitations with the tools currently in use. This means you need to learn critical thinking, skepticism, to take wider perspectives.. Besides listening and doing you need to learn to ask, propose and argue.
It is a problem that some BSc or MSc (or BA, MA whatever) may never be exposed to this culture of critical thinking and become experts/pundits with narrow perspectives and a lack of skepticism.