Doing research with undergraduate is currently very valued: at small schools, as JSE points out, because it helps improve the educational experience f your students. At larger schools, bringing in outside undergraduate students in the summer is a great way to advertise a graduate program. Including a solid undergraduate project always improves a grant application.
At the same time, undergraduate research cannot take the place of your actual research. I think that most people who are serious about UG research would agree that UG research in math should be primarily about the student's experience and growth, which means that more often than not the actual science will have to take a back seat to making the student a better mathematician.
It sounds like you're afraid you CV has too much of that. You can rightfully boast about this, but I would make it clear that this is not intended to be your whole research program.