As long as the Pittsburgh Penguins have Sidney Crosby and Evgeni Malkin on their roster you know they are going to construct the roster around them with the goal of winning the Stanley Cup. That is why they are so willing to trade first-round draft picks, why they are so willing to trade prospects, why they are so willing to overpay free agents with too much term if it helps them in the short-term.
They want to maximize the years they still have with their two Hall Of Famers.
It is the only way for them to build. Anything less than that is a disservice to the players, the fans, and the organization.
Having said that, as Crosby and Malkin get into their mid-30s there is going to come a point where they are no longer able to carry the offense quite as much as they did during their prime. Now, this does not mean that they will cease to be productive or that they are going to be any kind of a drain on the roster. They will still continue to be the players that drive the bus and lead the offense, and they will continue to be legitimate top-line players. The greats do not stop producing points entirely just because they get a little older. They just may not be scoring champions.
If you look at the NHL’s history of scoring champions, and players that contend for scoring titles, they are almost always in their mid-20s or younger. It is rare — extremely rare — for a player to win a scoring title at age 30 or older.