Well, I beg to differ. Nannies can provide everything that a creche can, and more. Nannies offer one on one attention, which is very important to developing children. At age 1.5/2 years, then a child should be introduced to a creche/day care for a few days a week for the social interaction. However, they should also have play dates with the nanny, and other children, which during the first 1.5/2 years provides enough social stimulation. As you can see, that is what they have done with Christian.
Please explain where you find the benefit in putting an infant in day care? As a general rule the ratio of teacher - children before age 5 is 1:4 or 1:5. At that ratio, an infant generally spends most of the time in a crib, or on a blanket in the play room with very little interaction. I think that the one on one that a nanny provides is far superior to a developing child.
A qualified nanny has generally very similar qualifications or more than a day care provider. They have training in early childhood development, childhood nutrition, and a myriad of other things that qualifies them just as much if not more than a creche teacher who often is just someone straight out of college with little to no practical experience.
I am sorry, but I do not see the benefit of day care over creche for young children. Social skills, sharing, and the like can all be taught at home and with play dates just as well.
Have you had any experience with nannies? If not, please don't generalize them. Nannies are a best case scenario for people who want to do the best for their children, and either can not afford to stay home full time, realize that they are a better parent with the interaction that they get from the workplace, and want to make sure that they give their children as much one on one time as they can, which an informed parent knows will not happen in a day care. If a parent stayed at home, the child would receive that one on one. So I do not understand where you feel that it is okay for a child to stay at home with a parent, but when that parent makes a reasoned and fair decision to bring someone in to give the child the personal time that it is wrong. I am not criticizing anyone for putting their children in day care. Day care is most often far cheaper than having a nanny in the house. And I agree that day care is a good option for a few days a week after age 1 or 2.