A few things which are relevant to whether criminalising a practice will be useful:
- Is the practice already culturally embedded?
- Can perpetrators be identified and will they be prosecuted?
- What are the unintended consequences?
If a practice is already culturally embedded, unless enforcement is very effective / likelihood of being caught and punished is very high, people will continue that practice even if it is illegal.
At the same time, if the practice is criminalised, those who seek it will go underground, where it is more likely that criminals / those without any scruples will be the ones carrying it out, and conditions for the procedure will deteriorate. Additionally, you introduce a barrier to care seeking if the procedure has complications.
The practice continues, but as a direct consequence of the criminalisation, more babies are seriously harmed and die. The entire moral grounding of making the practice illegal, is to prevent, not cause that outcome.
So though I also feel very strongly that non medical infant circumcision is wrong, and would love to live in a world where it is not practiced, and is criminalised - I don't think we are at the point where criminalisation will do more good than harm.
Before criminalisation can occur, culture change must occur. Education and community engagement achieves this, in the meantime, regulation mitigates the harm.