I agree that LEED doesn't necessarily result in a building that uses "significantly less electricity or have significantly lower greenhouse-gas emissions," the point system allows designers and developers flexibility in how they approach incorporating "green" practices which often allows less than perfectly green results.
However, as a LEED AP, I've taken the approach that the LEED rating system is more of a discussion starter than a definitive guide to going green. Many of my clients have only been open to reducing the heat island effect, incorporating recycled materials, and having onsite solar panels, because of the LEED point system. No commercial developer wants to reduce parking capacity, but it is a relatively easy LEED point to achieve. Pervious paving systems require maintenance and building commissioning costs money, but the benefits of keeping water out of the municipal storm water system, keeping pollutants onsite, and having a properly tuned HVAC system shouldn't be undervalued.
No rating system will ever be perfect, but as a way of having dollar conscious developers begin to change their thinking, I think it's the best thing we have.