The laws governing any practice have to consider and mitigate the worst possible outcomes for everyone involved. For example, I have to be insured to drive my car because the worst possible outcome is that I make a mistake and cause someone a life-long disability.
In the case of surrogacy, the worst possible outcomes include, without being limited to:
- Disability of the surrogate mother from pregnancy complications.
- Refusal of the commissioners to adopt the child.
- The surrogate mother needing an abortion or early delivery to protect her life or health.
- The child being born disabled and the commissioners blaming the surrogate mother.
- Pregnancy loss that the commissioners blame the surrogate mother for.
The law has to consider and mitigate the following possibilities solely because there are commissioners involved:
- The commissioners attempting legal action against the surrogate mother for perceived negligence during the pregnancy leading to miscarriage or the child being disabled.
- The commissioners refusing to adopt, leaving the surrogate mother holding a baby she didn't expect to be raising.
- The surrogate mother bonding with the child and refusing to permit the adoption.
- The commissioners attempting legal action against the surrogate mother because she had an abortion.
- The surrogate mother attempting legal action against the commissioners for a disability incurred from the pregnancy.
It's not possible to craft a law that prevents all of these adverse outcomes, other than one that says "surrogacy is outlawed". If you allow surrogacy but prohibit contracts between the commissioners and the surrogate mother, you prevent 1, 4, and 5 at the cost of permitting 2 and 3. If you legalise contracts to prevent 2 and 3, you open the door to 1, 4, and 5. Legalising contracts is deeply problematic for a second reason: it would create a situation in which babies are de facto transferrable property, which is at odds with their basic human rights.
You might trust your in-laws to do the right thing but other people with different moral values exist and there are already documented instances of commissioners rejecting babies. The law is there to protect us all from the immoral people, not the moral ones.