Separate the risk from the dislike

Write down what specifically worries you, and be honest about which kind of worry it is. Some are checkable risks: this field has poor employment outcomes, this institution is not recognised, the numbers do not work. Others are preferences: it is not what I imagined, it is not what people in our family do, I would not have chosen it.

Both are legitimate feelings. Only the first kind is an argument. Mixing them is why these conversations go badly — you raise a real concern about outcomes, your child hears the preference underneath it, and the actual point never gets discussed.