I think a lot of people, myself included, are acutely aware of this... which is why I adopted an adult rescue, not a puppy. Not everyone does it that way.
The problem isn't so much having to deal with the dogs that have already been manufactuered, they should be supported as well as possible, the problem is stopping the ongoing manufacture of new animals as products.
What does your ideal world look like? Dogs and humans have no relationship? Humans stop interacting with the animals we have domesticated and return them all to the wild?
I don't think there's a large constituency in this thread who's in support of "manufacture" of dogs in the sense of things like puppy mills. But that isn't what we're talking about with shelter dogs. Nor are dogs simply going to cease existing if we decide as a society that we don't want to continue our relationship with them.
The problem isn't so much having to deal with the dogs that have already been manufactuered, they should be supported as well as possible, the problem is stopping the ongoing manufacture of new animals as products.