We could end up with a society of only straight people—or the opposite—depending on our meta-level preferences. In fact, it would also probably be feasible to turn anyone who wants completely asexual
Arguably, the opposite of straight is asexual. At least, not wanting sex with anyone is more clearly opposed to wanting sex with members of the opposite sex than wanting sex with members of the same sex (which is what I assume you meant) is. One person can do both of the latter, but not both of the former.
Anyway, as far as meta-preferences go, by the time all of these parameters can be fiddled with at will my preference is that we be primarily concerned with something else, such that your question feels roughly equivalent to “should we prefer to peacefully coexist with people who mix stripes and plaids, and whatever other combination comes up, or should we settle on something boring like all-leaopard-print or all-sequined?”
Arguably, the opposite of straight is asexual. At least, not wanting sex with anyone is more clearly opposed to wanting sex with members of the opposite sex than wanting sex with members of the same sex (which is what I assume you meant) is. One person can do both of the latter, but not both of the former.
Anyway, as far as meta-preferences go, by the time all of these parameters can be fiddled with at will my preference is that we be primarily concerned with something else, such that your question feels roughly equivalent to “should we prefer to peacefully coexist with people who mix stripes and plaids, and whatever other combination comes up, or should we settle on something boring like all-leaopard-print or all-sequined?”