Because they need a #2C. We will still be in great shape for a repeat if all we do is get a quality 3C. But there are teams out there that legitimately need a top 6 center. Those teams will be more desperate and willing to offer up more then us.
Honestly, I'm not sure about that. There are teams that probably need him more than the Penguins do, but the Penguins are much more likely to win this year. Would a team go all in on Brassard if they're not going to win in the next 2 years? I don't think so. Need is one thing, but you also have to look at Brassard's contract and question if he'll make a big enough difference where you can justify paying that much for him.
Let's use Carolina as an example. They have a much bigger need for Brassard than the Penguins do, without a doubt. On the other hand, Brassard is a free agent after next year. Are they going to pay a lot for him, when they're not even in a playoff spot and Brassard isn't committed long term? Yeah, they desperately need an offensive top-6 center, but that's a huge gamble to make on a player with that little control.
I did see a reasonable suggestion from the main boards when it came to Brassard. Columbus trades Johnson for a 1st (which they apparently have on the table right now), and then use that 1st and a prospect like Abramov for Brassard. I think that's a reasonable suggestion, and I don't think Columbus would shy away from doing that because they're not giving up a ridiculous amount for Brassard.
Cullen, Pouliot, Letestu, Grabner, E.Kane, Brassard & Pageau.
A quote re Brassard: "While they think highly of Brassard, they aren't trading their top pick, Daniel Sprong and another player on the NHL roster for Brassard."
Change Sprong to Gustavsson and I wonder if they feel the same way.