I admire your honesty and you're pretty much correct in what you say.
The fact is that the hounds are bred to hunt and when it's no longer economically viable to keep them they are indeed deemed to have "served their purpose" and then destroyed. It begs the question then as to why the hunt...
Having read through this thread, it comes as no surprise to me that you've asked this perfectly legitimate question THREE times now and still not got an answer.
Unless I've missed it, and someone actually has answered you, I think you could go on asking the same question over and over again...