Because a company looks at what their emplyees do. A union offers legal action and protection. A company doesn't want that. When the pilots vote it down they send a message that they are selfish and not looking out for the whole. The company now knows that 65% of the pilot group is happy with current conditions. So now they aren't obligated to make them any better. What the pilot group does as a group shows how much the company can bend them. Take Pinnacle for instance. They were approved to strike. If the opportunity comes, and they back down now after all the publicity, the company will know they can walk right over them. A strike isn't anything they want, however since it has been approved they need to do it should it come to that.