Same logic applies to whites, Asians and every other ethnicity. Suppose this guy is the man of your dreams, perfect for you in every way--are such men so common and easily replaced that you'd pass one by out of some vague obligation to black women everywhere? It's the nature of the beast; every time someone finds a precious gem of humanity among the broken dross that is seemingly 90% of the species, one less is available for everyone else. From the standpoint of brutal statistics he's not much more likely to find Claire Huxtable than she is to find Cliff. That may be one reason he's not limiting his dating options to his own race, and if he's not worried about how many "eligible" black men are available for black women, why are you?

If he's somehow "meant" to be with some as yet undiscovered black woman ideally suited to him, nothing you do or don't do will prevent that; if not, pursuing a future with him costs neither of you anything, but refusing to do so could cost you both a great deal. Regardless, refusing to date someone to whom you're attracted, on the grounds that it's "inefficient resource allocation" because another girl would be very happy with him, seems like self-sabotage. Again, I think there's "a dearth of eligible" men and women in every race; what are you gonna do, exclusively date abusive unfaithful ex-cons so other women have a chance at happiness? Why not show yourself the same courtesy and compassion you show them?

For the record, no, I haven't dated outside my race (as such; as Americans, everyone but fellow mutts, including my wife, is "outside" our "race" ).