I don't think this is a fair comparison because we breed these animals for farming, so technically we could breed as many as we need to sustain our habits.
On the other hand there is no way to breed whales. There is some finite number of them in the wild and we cannot actively endeavor to create more.
Commercial farming of farm animals will not cause the extinction of farm animals; commercial farming of whales will cause the extinction of whales.
It's incredibly expensive to do this. Most people can't afford it especially since one of the parents generally has to spend most of their time with the child forgoing work.
Yes, there are programs in most states to help the parents in this sort of situation, but most of these programs let the benefits run out when the child reaches around 21-25 years of age.