Starfleet recognized what she accomplished in the Delta Quadrant. The specific rank seems to be an arbitrary choice on the part of the writers. === Some would say their achievement eclipsed even those of the legendary Enterprise command crew === It's still not as far-fetched as alternate Kirk going from cadet to captain in a matter of days.
^^ I suppose you weren't paying attention to the part of Star Trek where they showed in large letters "THREE YEARS LATER"
- not that it has anything to do with the question, but he was still a cadet after the 3 years, it's a 4 year school.
- Also anyone that commands a ship is referred to as "Captain" regardless of actual rank.
In the course of returning to Earth, Janeway destroyed Unicomplex-01, killing TRILLONS of Borg drones, and wiped out the Collective's Transwarp Network. If that didn't deserve a mega-promotion, nothing did.
It was also mentioned that she'd commanded other ships before, and held the rank for quite a while. If she hadn't been tapped in the Delta Quadrant, she might have very well been promoted anyway. Also, Voyager missed the entirety of the Dominion War. There was surely several unfilled flag billets in Starfleet, and when this very experienced officer returned, she was a good candidate for an accelerated promotion.
Another important note is that nowhere is it mentioned she jumped all at once. Voyager returned home in the first few day of 2378, and her next canon appearance is in late 2379. She might have been promoted more than once in those intervening two years; rather rapid, but more plausible than skipping ranks (though it does happen).
To expand upon an earlier point:
- She maintained the prime directive without any federation to back her up; she was alone.
- Unified Maquis and Starfleet crews under one flag.
- Had more 'first contact' situations than most Starfleet Captain's usually see.
- Made allies of numerous races in the Delta Quadrant.
The list could go on.
Everyone else has made the objective points fairly well, but I'd like to mention how I think Janeway is one of the best captains, far better than kirk or picard, and just about tied with sisko. She's got a lot of emotional depth, cares about her job, and connects to her crew better than any of the others. The one point which makes her lose, (albeit narrowly) to Sisko in my book, is that she has a bit of Picard's pride which periodically leads her to try to "go it alone" without keeping her crew informed, which is an awful plot device that was overused with picard, but mercifully not with sisko. Ben by a nose helped along by his tragic past and capacity for realism. I like guys with a sense of loss, tragedy, and failure, but who still keep trying. Kirk is too cheery, Picard too emotionless (to his crew), and Janeway a tad stubborn. That said, she's much more responsible than Kirk, and more visibly compassionate than Picard. When you consider her record under extraordinary circumstances, she's awesome!
She's awesome!! I don't think any of the other captains could have done what she did. Totally deserved promotion.
- Kept most of her crew alive for seven years in the DELTA QUADRANT. (Not in nice safe federaton space like Picard.)
- She made maquis turn Starfleet.
- She didn't break protocol very much.
- She made loads of first contacts.
- She was nice to her crew and showed emotion.
- As mentioned above a lot of officers were probably killed by the Dominion so there was more promotion opportunity.