Whether or not we are to oppose a cultural system depends on a variety of factors.
Detailed Analysis of Adaptivity
Most cultural systems have some maladaptive nature. For instance, any collectivist system is going to help induce an increase in reciprocity towards in group members while causing a decrease in cooperation between different groups.
It’s easy to want to oppose a system because we see that it causes some harm. But whether we keep a specific cultural system, or we oppose it, is not a matter of individual elements, but rather the net impact. If we only looked at one side of the equation, we’d have to call medicine harmful. There’s malpractice. Some medical studies have been conducted in very immoral fashion, there are side effects to various treatments, and so on. But the net impact on society is positive.
Even if alternative systems could provide the same benefits, there is no reason to remove the system, unless doing so produces a net positive impact on society. But measuring that impact is very difficult. We have to look at a wide range of conditions, determine whether those conditions are specifically due to the cultural system, and then sum the effects of all of those conditions.
There is one reasonable proxy for determining the net impact of a cultural system, assuming that it has been around for an considerable period of time. That proxy is the fact that it has been around for so long. Cultures evolve much the same that biological systems do. Richard Dawkins coined the term “meme” as the cultural analog of genes. It is the meme which conveys information and which is the target of selective pressures.
Just as natural selection weeds out genes which produce net harm to a species, so does cultural natural selection weed out harmful memes. A cultural system which provides net harm to a group of people will naturally die out over time. If the system has exited for millennia, then either it is an inherent emergent property of the human species, in which case elimination of the system is essentially impossible, or there is no negative net harm.