Desires are desires. Both are born out of a need for fulfilment. If there is no need for satisfaction, then there will be no desire. Desires only indicate a need for satisfaction in a person's life. Whether our attention is towards material gain or spiritual gain is another matter, but desires provide a motivation for one's actions, one's karmas. Appropriate desire combined with action leads to fulfilment. The question is how to guide and direct the desires, and that is the real training.
In Yoga, desires are not just blindly followed, but rather are used to uplift the personality. In normal life, people blindly seek to experience contentment by fulfilling every desire, no matter how insignificant it may be. As we progress in spiritual life, we learn to contain the aspect of our nature which craves fulfilment through whatever means possible.
