I feel that you (we) buy them because we love them and respect them so much we can't stand to see them abused.
I disagree 100% with the notion that stored in a loving home is no better than a dump. That to me sounds ridiculous.
for me the secret has been to put as much effort into rehoming as I do into searching for new ones to be rescued.
I would think that the key is to make sure that the machines being rescued is still causing you joy rather than anxiety