It would have been less silly if they just ended the last movie with a medal, fleet wide recognition as a badass, and a promotion to commander at the most, and then just opened up the second movie with him as captain or becoming captain.
That would be like if in the star wars prequels, during the first movie anakin turned into darth vader because someone threw away his action figures as a kid and he snapped. However the star wars prequels sucked ass for many other various reasons.
This sums ir up for me, although I would have liked to see the final scene following the medal pretty much the same but with a caption saying 'Three years later' where Kirk strolls onto the bridge and looks around like he's come home and Spock elects to remain on the ship as his first officer.
Anakin's fate in SW3 is also the thing I liked least about the prequel trilogy. It was fine to see him descend into rage-fuelled wickedness but it would have made more sense if Padme had dumped him earlier in the movie. The biggest error in my view was naming him as Darth Vader and explicitly tying the prequel up in a bow ready for the sequel trilogy. We don't need to know who Vader is now, we will find that out in Empire. We don't need to know who Luke and Leia are, we find that our in RotJ. IThe last half an hour of the movie is just revealing spoilers to my future grandchildren. What were they thinking and why haven't they released an anti-spoiler cut of the movie - dammit! Leave Anakin burning on the side of the volcano as his final scene and move on. Why do they think that modern movie audiences need things spelled out so explicity?