Omnipotent being Q does Starfleet a favour by warning them of their new arch enemy - the hive-minded robotic Borg. Q catapults the Enterprise towards a giant cube-shaped Borg vessel. Here, the Enterprise can investigate the hibernating Borg before their ultimate invasion into Federation space two seasons later. Recall: At the beginning of the entire Next Generation show, we are shown that Klingons stop being the Federation's (Starfleet's) mortal foe. A Klingon even serves aboard Starfleet's flagship, the Enterprise. As a result, there seems to be no more reason for Starfleet to be organised as a military hierarchy. Vessels could explore space independently from now on. Klingons pose no more threat to unaffiliated travellers. As a result, it remains unanswered as to why Starfleet does not disband into independent starships. We are told in the later Star Trek show 'Voyager' that the Borg are e.g. Not interested in attacking weak species, such as the many Kazon sects. Therefore dissolving would have been a (another) solution to surviving the Borg. Admirals go home. Really, it's you admirals the Borg seem to want.