Rough day for DL at SJC this AM. Our 6:15 departure to SLC had everyone kicked off after being boarded. Pilots saw ice on the wings that had settled overnight. They had 3 de-icing trucks, but all had become non-operational. DL said they know about it but it didn't have priority from the airline to get fixed. Messed up our day substantially. It hurt to watch all the other airlines get their flights out. Questionable management decision by DL. Hope they don't make a habit of this.