I agree with what you are saying up until the last part because "traits" as a general term are not all positive.
As an example, we stigmatize, and should stigmatize, the behaviours of those who are attracted to minors, and that stigma likely does reduce the social transmission of those behaviours.
The question I think comes down to essentially whether one considers the results of acting on gender dysphoria to be "bad".
If it is bad, then the question then becomes, is it a net benefit to stigmatize transitioning - i.e. do the benefits in reducing overall gender dysphoria outweigh the costs to those who would have it regardless of social factors.
As an example, we stigmatize, and should stigmatize, the behaviours of those who are attracted to minors, and that stigma likely does reduce the social transmission of those behaviours.
The question I think comes down to essentially whether one considers the results of acting on gender dysphoria to be "bad".
If it is bad, then the question then becomes, is it a net benefit to stigmatize transitioning - i.e. do the benefits in reducing overall gender dysphoria outweigh the costs to those who would have it regardless of social factors.
If it's not bad, none of that matters, crack on.