Elias Vaughn wrote:
All true, but there was some dissension on the topic; I think it was Admiral Shelby who scoffed at the idea that the Borg could adapt to something that kills in one shot. Janeway could have thought something similar.
No, Janeway was familiar enough with the Borg to know they'd adapt to anything in time. But of course she couldn't possibly have known that the Borg would find an alternate route to the UFP as quickly as they did, leaving the UFP so little time to develop further defenses.
In fact, if I recall Homecoming/The Farther Shore
correctly, didn't Starfleet Command pretty much shut the Voyager
crew out of the process of researching and developing the enhanced technologies they brought back from the Delta Quadrant? Given the choice, Janeway would probably have pushed Starfleet to develop anti-Borg defenses faster because she understood the continuing threat they posed, but Starfleet was still recovering from the Dominion War and was maybe reluctant to face the prospect of another existential threat so soon, so they dragged their feet on it. So if anyone was complacent about the threat from the Borg, it wasn't Janeway.