I feel that correct usage of spurs by a knowledgable rider who is trained in their usage is perfectly acceptable. For instance, I NEVER used to ride with spurs until I bought my first horse. He was a Western Pleasure show horse and relied completely on spur cues and neck reining. He is able to be ridden with no bridle and just guided by leg and spur. Because of his extensive training with spurs and their cues, I have to ride him using spurs. Of course, I could probably go through through time and training to make him responsive to certain cues without spurs, but frankly, he is quite unresponsive to cues to lope or canter if I decide to push him out if I do not use spurs. It makes riding for me much easier and efficient and it is easier for him as well since he clearly understands exactly what I am asking. I just have to use a small, dull spur on him. My cues are extremely light and with the slightest touch of my spur(s) he knows exactly what I want. Sure, I CAN ride him without spurs, it's not like he'll just stand there, but they make it much easier to get the message across. It's like anything. Spurs can be abused, crops can be abused, bits and reins can be abused, lunge whips can be abused, and the use of our hands can be abused. All of the above are aids to send cues and all of them can be used both correctly and incorrectly.