Maybe it can also cause progress? For instance, the condemnation of Apartheid by the western world probably helped end it.
(I don't mean to say arranged marriage is the same as Apartheid, obviously.)
What I just wrote may be controversial, but it does not make it false.
The difference is to what degree does another agent, external to the system in question (here, the system that has apartheid), feels they have the right to intervene and accelerate the change in a direction they judge is fit.
Sometimes you can argue that everybody is better off -- people inside the system and outside (on the outside, I would argue it is mostly a psychological benefit, at least immediately after the change is induced) -- but the arguments are never perfect. And to think that there is a "correct" side to it is (usually) a fallacy.
Is this actually a valid use of "Reductio Ad Hitlerum"? Surely such a thing is rare and beautiful.
Outsiders attempting to generalize, analyze, dissect, and fix things about cultures they barely understand more often than not cause historical and irreversible damage.