I wouldn't worry too much about it, I don't think anyone here is advocating a culling anytime soon. But, the werewolf culture would seriously seem to lend itself to such a practice. Everything we've seen about them shows them to be a very physical, active species. They are also acknowledged as having more extreme emotions, and as having strong senses of honor and duty. They also live in an extreme climate.* And this condition also makes the sufferer psychologically unstable, moreso than even a normal werewolf. If you wanted to present a culture which acknowledged the practical necessity of only saving children who will one day be able to physically contribute in an equal sense, they would work very well for it. With the orc example, it's a valuation of a girl only for her reproductive capacity, which is a totally different cultural concept.
Like Veridis Quo said, it's not supporting it in real life. Hell, I've used this argument as one of the reasons I value technological progress and wealth accumulation, since the surplus allows us to ensure that a person isn't valued by how much labour they will provide. And the fact that they do have a culture with established institutions, such as universities, implies that the scarcity aspect of their culture no longer exists. So, is it a remnant of an earlier ages? Are there people advocating against it? Did Milov face a backlash from conservative clan-leaders for saving Katya? What happens if she flips out and kills someone, attributed to her being a "runt"? It could have been an interesting story to write. Just not by Mookie obviously.
* which is stupid by the way, I just want to be on the record as saying. Nowhere on Earth is there a land covered in perpetual snow, at least no where humans live. It's a really stupid fantasy cliche to assume everything north of 49 degrees latitude is forever covered in snow and ice. but this is just nitpicking