It seems to me that selection of a moral point of view is similar to selection of a car to buy. There is no such thing as “the right car to buy”, although there are probably lots of “the wrong cars to buy.” Selection of a car is neither a purely subjective matter, nor is it a purely rational and objective matter. Selection of a moral point of view is also neither a purely subjective matter, nor a purely rational and objective matter.
There are reasonable criteria that can and should be considered when deciding on a car to buy: price, other costs (insurance, taxes, maintenance), economy (estimated miles/gallon), performance, safety, comfort, reliability, and style/appearance. Of course, different people will place different weight or significance on different criteria. For some people who have lots of money, price, other costs, and economy may be of little importance. For some people who like to live on the edge, safety may be of minor importance. For grandmothers who just plan to drive a mile or two to a grocery store once a week, performance may be unimportant. But, in general, people agree that these are all relevant considerations, and in general, people will take all of these considerations into account when making a careful selection of a car to buy.
If two cars are for sale, and they are both exactly the same in all of these relevant respects, except that the price of car A is 40,000 dollars, and the price of car B is 20,000 dollars, then car B is a better choice than car A. This does not mean that selection of car B is the right or correct choice, because there are other cars with other configurations of features and characteristics to choose from. But at least we can make a comparative evaluative judgment that is objective.It might not be quite so easy to identify the criteria for selection of a moral point of view, but it seems in principle a similar sort of evaluative process. Suppose we are considering moral viewpoint A (= MVA) and moral viewpoint B (= MVB). Suppose that we determine that if society X adopts MVA this will probably result in widespread misery and suffering for people living in society X. Suppose that we also determine that if society X adopts MVB, this will probably NOT result in widespread misery and suffering for people in society X. Given this information, I think we can reasonably conclude that it would be better for society X to adopt MVB than to adopt MVA, other things being equal.
As with cars, there are not just two alternatives to chose from, and as with cars, there are multiple criteria to apply, multiple considerations to weigh, and different people give different weight to different considerations (the classic example being the tension between individual liberty and social stability). So, just as there is no “one correct car” to choose, there is no “one correct moral viewpoint” to choose. But we should be able to articulate criteria or relevant considerations that bear on this decision, and we should be able to make at least some comparative evaluative claims, like “moral viewpoint A is better than moral viewpoint B in such-and-such respect.”