For many students, the answer is "to get a visa to move to a first-world country".
If you're a smart first-worlder, there's many careers more lucrative than scientific research, so you'd only go into it because of passion. But if you're a smart third-worlder, a scientific career is often your best shot at emigrating to a rich country, so it becomes rational to do it whether you're passionate or not.
If you're a smart first-worlder, there's many careers more lucrative than scientific research, so you'd only go into it because of passion. But if you're a smart third-worlder, a scientific career is often your best shot at emigrating to a rich country, so it becomes rational to do it whether you're passionate or not.