Research professors spend much more time doing research than teaching. Usually you love doing it which offsets some of the monetary compensation issues. Also,

Research professors spend much more time doing research than teaching. Usually you love doing it which offsets some of the monetary compensation issues. Also, "barely get any pay" is relative. It depends on where you live, the type of school, the department, seniority, and in some cases whether you do something like spending your summers consulting.