Pittsburgh's the 4th highest scoring team in the league, with two of the 5 best offensive players in the league.
I understand the need to "score to win", but you're not going to beat them 7-6... you need to play solid defence (or get ridonkulous goaltending) to beat teams like that.
And anyways, all that being said, if Maclean thought he needed to shelter his barely-20 year old rookie defenceman against a team that can throw Crosby and Malkin at you back-to-back, to avoid putting a kid into a situation he thought might be too much for him while he's still learning the game at the pro level, I can understand that decision as a long-term strategy.