Precisely, its still a useful tool in describing the disparity between survival strategies two organisms have, or even organisms within the same species. To be precise, no one is dominated by r-selected attributes. We're a species that's certainly overall, effectively K-selected. Afterall, in the animal kingdom, we're champion Dads. It's more that certain people have r-selected tendencies, i.e conflict and competition avoidance, promiscuity, reduced in-group preference, etc.
In fact, there's a Rogan podcast with Sebastian Junger, whom describes it beautifully as it applies to people, though he doesn't reference r/K selection out-right.