Yes, it is protecting existing families. As the law is applicable for concrete situations that have to be solved right now, and not in a coulda woulda probably at some point future. And of course, fertility treatment is free in most german health insurances (at least half of the cost has to be covered by law anyway), so there is no significant cost attached to that procedure. The law simply requires to take into account what exists right now, and yes, its aim is to protect kids and families, those that do exist. There is no question about the reason behind the kids being there or not, that is indeed a personal matter, just if they are there, they are to be protected. It is not new by any means, that law has existed for many decades, just the points in approved point systems have changed over times to reflect the increasingly lower number of kids, which makes them more important and therefore valuable. As each european working law is very much different, there are always more thinks to take into account before moving to a country and working there than just the contract itself.