AIUI, the reason that courts order cooperation for this sort of thing is that every party deserves the right in court to defend themselves as best as is possible. If in order to defend themselves they require information that they cannot present themselves but that someone else can (say your alibi was being at work - your boss could confirm that), then it becomes that party's civic duty to cooperate with the courts and make sure that the appropriate information can be yielded to ensure a just decision. If there are concerns about cost or potential secrecy/privacy implications, someone who is subpoenaed can bring that up with the judge who can then work with all parties to appropriately manage the situation.