I wouldn't dream of lecturing someone for something they might not be able to control, but I do think people should be aware that one is a better option than the other. However, I also understand that it can be a sensitive issue and that there's a definite tendency for parents to criticize other parents in ways that are completely reprehensible, though. This extends to all parenting decisions, but people get particularly rabid about choices regarding health in infancy (eg. breast feeding, circumcision).

If you ever want a more neutral perspective based in science, that's what I usually try to provide for people. I try to stay up to date on most studies... allergy precautions, for example, have changed drastically in the past five years- whereas physicians used to believe that in order to prevent a child from developing peanut allergies one should withhold products containing peanuts until later in development, there is now information that suggests the opposite is true, and that withholding peanuts increases the likelihood of developing allergies.

But I'm not a parent, so I suppose that takes the personal investment part of it out of the equation.