Sorry but I find this just fundamentally wrong. They're can't be an excuse for every single situation where a trade is mentioned, and there's too many other factors.
1. Players aren't evaluated only on the last month or so. If the Bruins think DeBrusk, Heinen, Donato, etc. are good enough to play top 9 minutes and have bright futures, it could EASILY be the case that other NHL teams view it the same way. Thus, they could absolutely want those players and value them highly.
2. Most NHL teams have "woes" right now. I think fans kid themselves when they say things like "we can't make a trade now, we're losing, we'll get fleeced!" That makes no sense. A competent GM knows he's losing, and other GM's might hope to get lucky, but they can't expect to. What goes around comes around, and it's a circle for all these teams. They all go through slumps and have needs. I'm not suggesting they help each other out, but the idea that a trade needs to be unfair depending on the relative level of desperation for the GM's seems like complete BS to me.