To quote a video game a friend of mine wrote, do you want to know what the definition of insanity is? Roughly speaking, it's trying to win year after year with the same core of "stars" that has failed to make the playoffs in ages.
Six years in a row. Eight of the last nine. That's how long the Hurricanes have been trying the "Well, if we just put the right pieces around Cam Ward and Eric Staal, we'll win this thing again". It almost worked once, seven years ago, when they Canes magically made the Eastern conference finals. Otherwise, bupkis. An unending stream of early season disasters, followed by midseason runs that served only to get hopes up before the inevitable end of year collapse. The last six years, they've come in 11th, 9th, 12th, 13th, 13th, and 14th. This year, they're on pace for 12th again, which is improvement only in the sense that a Michael Bay movie is an improvement on a Uwe Boll one.
And now, finally, they've blown the whole thing up, and it's for the best. Staal goes to the Rangers for draft picks and a prospect, a chance to kick-start the rebuild in earnest while Staal gets to go play for a serious contender and maybe get himself a late-career ring. Everybody wins, or at least stops losing in the same old way.
Eric Staal's a very good player, one of the best in franchise history. Depending on how you define the franchise (Whale? Yes/No) maybe the best. But he was never the sort of player who could carry a team by himself, certainly not year after year. An extraordinarily good player, but as much as he was the Hurricanes for a long time, not a great one. And that's OK. He leaves behind a lot of good memories and one magical Cup run, which is about as solid a legacy as one could hope for. It was just time to turn the page.