Defining our own good, and living our lives in pursuit of it, is at the heart of a moral life.
So what matters to Dr Cannold is not what we happen to choose but that we get to define our own good.
There were readers of this site who doubted Dr Cannold's sincerity. They pointed out that traditionalists aren't allowed to define the good as we would like to and that certain choices that traditionalists would make are disallowed. Dr Cannold and other liberals, these readers claimed, are therefore not following a logical philosophy and are asserting their power in society in an arbitrary way.
But I don't think that's right. The liberal system logically forbids traditionalists to choose the kind of society we would like to have (by "logically" I don't mean that it's right that liberalism does this, but that the outcome follows from first principles).
It goes like this. Liberals believe in a freedom to self-determine. Therefore liberals don't want things that are predetermined to influence what we can or cannot choose to do.
But qualities like our sex and our race are predetermined. Therefore, a common liberal position is that:
i) it is permissible to freely identify with these qualities privately, i.e. as a matter of your own personal life
ii) it is wrong to assert these qualities in ways that might limit the choices that other people make.
You can, therefore, identify at a personal level with your own particular ancestry, but it would be considered wrong to deny someone entry as a migrant to your country on the basis of race. Similarly, you can choose to identify as a man or a woman, but you cannot select for employment on the basis of sex. If you deny someone an ability to choose on the basis of an unchosen, predetermined quality like their race or sex it is treated as discrimination based on these qualities, i.e. as "sexism" or "racism," and as a denial of equal opportunity.
So it is no use for a traditionalist to argue that his good is to have an immigration policy that leaves him with an ethnic homeland of his own or that his preference is for an army that does not employ women as combat troops, as both of these options discriminate on grounds that are unacceptable within the liberal system.
That's why traditionalists have to dig deeper and challenge liberalism on the basis of first principles. The issue to be fought is whether a freedom to self-determine is really an adequate basis on which to found a society. Traditionalists would argue that individual autonomy is not always and everywhere the overriding good to be pursued. To make it so is ultimately dissolving of the particular society you belong to. A wiser policy would be to accept a range of goods and to order them so that the social framework fits together (works together) to the greatest extent possible.
A couple of other observations. This aspect of liberalism, that you can hold to something as a private feeling but that you cannot assert it in a way that might limit what someone else can choose, explains those liberal politicians who talk positively about their own ancestry whilst enacting "non-discriminatory" migration policies which spell the end of particular ancestral identities.
The former Australian PM, Malcolm Fraser, was reportedly proud of his Scottish heritage, but was also an open borders man. An earlier PM, Sir Robert Menzies, was famous for his regard for his British heritage but oversaw the transformation of Australia into a mixed European nation. Menzies described his affection for his British heritage as being "sentimental" (a private sentiment rather than an identity to publicly uphold). A more recent PM, Paul Keating, identified not only with his Irish ancestry but with a strain of Australian larrikin culture - but, again, was fervently open-bordered. I have even heard some serving Labor MPs speak positively of their UK connections, but it would never cross their minds that such identities should be upheld through migration policy.
Finally, the argument has been raised that liberals aren't sincere in wanting people to self-define their own good and make their own autonomous choices, because the liberal state is happy to intrude paternalistically in discouraging smoking or in making people wear seat belts and so on.
But the seat belt or smoking issues don't really contravene liberal principles as these do not deny equal opportunity in the manner I described above but are rather "neutral" health measures that apply to everyone equally.