Thankfully, I had a severe wake-up call a couple of years ago. I was attending a very small local fair and there was a well-turned out lady with a well-turned out horse and my bigotted thought was, "Well, they look good, for whatever that counts." When that pair went in the ring though, I just about fell on my face. They were amazing. I swear the lady was part and parcel of the horse. There was such amazing movement, connection and "tightness" in their action I was stunned. Blessedly so. I'm so glad that I saw what I did. It changed my outlook.
So, to any plus-sizer's that may think they can't do something because of size, skinny little me knows that it's just not so.