I can. By making it technically possible, you can divert attention.
One example would be for crazy edge situations. Like letting children with terminal illnesses fulfill their last wishes, or letting hormone ridden teens make their case to a judge, keeping them from more extreme actions.
But more practically, I think this is a great idea… 99.9% of anyone asking for this either needs court ordered mental evaluation and/or a referral to CPS to do a deep dig into the situation. By making it technically possible, that means anyone seriously pursuing this has to explain themselves to a judge.
Unfortunately our judicial system has a lot more to do with money than justice (so most people who would actually go through with this probably have the money to protect themselves from consequences), but this law would be a sensible part of a more perfect system… Granted this should almost never be granted by the court (terminally ill child is the only situation that makes sense to me), but there’s value in it
My opinion would change greatly if this is a real path to child marriage rather than a mostly theoretical possibility