I'm somewhere in the middle. I think if you want to truly leverage your prospect pool, you need to give them time to grow into the opportunity, reward those who are working hard, and truly give your prospects an opportunity to realize their potential, based of course on performance.
That's why I was all for Stanley getting in over Samberg. He's put the work in, he's doing what the org wants and he deserved his opportunity. Samberg, whilst being better prepared for pro hockey than many of our previous prospects still hadn't really had many reps with the team, and is brand new to the culture, systems, etc.
I do believe that Maurice tends to hold on to vets sometimes, however, I also think that it's overstated greatly on these forums, and I think that the benefits of veterans aren't understood to the extent that allows the average fan to truly appreciate their contributions.
EDIT: As for Niku, I also think it was the appropriate move to have him in the opening day lineup. This is pretty much Sami's last chance with the org. so it's good to try and confirm your assessment of a player as a team before moving away from them.