Spindly little legs probably won't hold up to much work with any size of rider, so those horses are best to avoid in the first place for anyone! However, when I am talking about "good bone", I'm not necessarily talking about the fat legged draft horse. Many stock horses have excellent bone and fantastic feet and are completely suitable, when coupled with a short back and general overall fitness for a plus sized rider.
I wasn't under the impression that that sentiment was what I was implying AT ALL. I am concerned now that other readers may have percieved it that way. Comment?