There were two Borg episodes prior to "Scorpion": "Blood Fever" and "Unity".
Blood Fever showed us the Borg corpse at the end, indicating they were nearby.
"Unity" was great because it's events are what allowed Chakotay to tap into Seven's mind and resolve the story.
And then after that, we get to Scorpion which tied into both stories quite well. What happens?
Folks whine endlessly over how there was a single alien species more powerful than the Borg.
You just can't win. Seriously.