I mentioned in another comment how circumcision dramatically reduces the rate of spread of STDs. That is, at least from my perspective, the primary (and original) incentive to circumcise. Significantly less of an issue now, because you can just get a condom. But in areas where access to a consumer profilactic isn’t readily available or one in which STD infection is high, it would make a great deal of sense to perform the surgery as a preventative measure.
Same as giving your kid vaccine shots or putting them in the NICU for the first few weeks of their life or demanding that they wash their hands regularly.