That's kind of sad, I think there's got to be even some Pens fans who would enjoy seeing him with Mackinnon and would take the 1sts for him.
Not that it also wouldn't hurt, but you'd get to see Sid playing for cups again.
I'd have to ask some Bruins fans whether they'd have preferred if Ray Bourque retired as a Bruin.
There is certainly a contingent of Pens fans who want Crosby (and Malkin & Letang) traded for future assets.
Myself personally as a Penguins fan, I just want Crosby to have his way whatever he decides... If he wants to go elsewhere I think the team needs to oblige him of that and make the move. If he wants to stay, then I think he's earned the right to have that wish granted to him.
His most recent 2-year contract extension has a full no-movement clause, so the team couldn't trade him if he didn't agree to it anyway, but I would be fully against the team trying to convince him to waive it and trade him against his desires.
I've got a similar attitude toward Malkin and Letang, but Crosby has always been the big dog here so he's the only one I think deserves for his word to be gospel in Pittsburgh.