Java (SunMicroSystems) and ActiveX (Microsoft) are two major technology platforms that has evolved itself a long way from years of R & D and support from the developer groups. In case of Java, Sun has invested a lot of money and effort to develop, innovate, maintain and release Java which can cater to all industry and personal Software Development needs.
More than any other party, Sun has the intellectual capability to decide and discern modifications and upgrades to the product. So it is appropriate to have them control the standards. At the same time, it is implied that control should not lead to monopoly and should provide ways for open collaborative efforts. Standard setting inherently avoids competition and adherence to accept the stuff in the way it is built by the winner. In such a situation, the imposition on Sun to make changes in public will ensure that the changes are creative and effective enough to gain public support inter-system compatibility.
Sun has opened Java under GPLv2 license which has lead to greater innovation by open sourcing all major Java implementations. Here is a nice reference for those interested in Sun’s efforts to Open-source – Sun Opens Java