If someone is being paid from research funds, then their job is absolutely to do research. For tenure-track faculty members, the salary of their job for life is paid directly from the taxpapers (at a public institution) or indirectly through government student aid for high tuitions (at private institutions). These faculty positions are sold to taxpayers on the premise that the facutly are engaged in educating students, so if they are engaged in mostly 'research' and little teaching, there is a problem.
It goes to the basic problem of modern academia - are you a researcher who teaches or a teacher who does research? At major research institutions, this is a major conflict because a large part of getting tenure is how well you do research and teaching not infrequently suffers. I think it’ll probably come down to eventually separating the two jobs of teaching and research at some point.