This is a cull plain and simple. Please appreciate the specific and God-given role of the predator in nature. It's natural and it is sublime.
The cubs are adorable. It makes nature's wrath that much harder to comprehend.
I don't make up the rules of nature. I just observe, interpret and marvel. Rest assured that if man did not intervene, another entity would.
It would be best to just ignore the seal cub happenstance. Any human intervention to stop the culling would certainly lead to far greater short-term hardship on the cubs, as is the normal vector.
Of these thing, I do not know why. It just is and any human intervention tends to complicate the situation with more dire circumstances for the indigenous animal population.