For the sake of argument, if I accept both of these as true, I think that the second outweighs the first. Being better in the short term isn't important for the Canucks, but the long term is.
But I actually don't believe #1 is true. That's not to say that the players are bad, but, rather, that they're not what the team needs. Beagle in particular, as analysts on CanucksArmy and Pass it to Bulis argued, is a redundant asset; the team already has a centre whose only effective role is strictly defensive. With those players in the line-up, the scoring problems are going to worsen.
The team has replaced Daniel, Henrik, and Vanek with Roussel, Beagle, and Schaller, none of whom has the skill to play with and help develop any of the incoming younger players. In the short term, the Canucks would have been better off doing absolutely nothing.