He intentionally dodged ethical review and the law, the consent forms he had the parents' sign obfuscated the nature of the treatment, the experimental treatment offered no benefit over the currently used treatment to prevent HIV transmission from the father (sperm washing), the parents likely only agreed because the law prevented them from otherwise having biological children (IVF isn't available to HIV+ patients in China), the high risk of modifying non-target genes was well known, and he knew that the gene he introduced is believed to be linked to neurological differences.

Because it didn't work and he fabricated his research

I don't enjoy the idea of babies given circumcisions, I can't abide genetic tailoring by a person internationally decried as an unethical practitioner doing things in secret just to stoke his ego to make him the first, bypassing the incredibly necessary ethical safeguards that the industry enforces against themselves.

I don't want him to be able to do what he did in the way that he did it because the way that he did what he did allows for monstrosities to be committed in the name of advancing science at any cost with no thought to potential lifelong unknowable direct consequences in the people being treated.

I don't have an anti-genetic editing slant, I don't think the goal is bad.