I know! I could maybe see if she were some crazy horse that charged people, kicked, bit, struck and reared all the time. That would classify as dangerous. However, I have worked with horses that were not good with their feet and there are many ways of training them out of it. And ways that are pretty safe for the handler too. By no means did I think any of them were a right off and should go for slaughter.
But I do see the others view point in that she might have other issues we don't know of. Maybe they aren't telling everything.