This is one of my pet gripes. Penicillin is something I know works for a variety of diseases. I know it is anti-bacterial but somehow it works on colds, ear aches, sinus problems---why I don't know but it does. As a child in the late 1940s to early 1950s it was given universally. Then they began substituting other drugs and telling us we needed to cut back on penicillin, to be used only in the most dire cases, so that bacteria will not develop immunity.
But I don't think this is all of "their" reasoning. I think if you are a member of the elite class, whatever that is-politics, medicine, insurance elites--I don't know for sure, but if you are an elite member, your child can get all the penicillin they need. In other words they are saving this for themselves and their children. Your child gets an inferior substitute so the possibility of immune bacteria is lessened FOR THEIR CHILD.