Big name free agents don't want to come to Boston. That's not going to change because the team wins 4 more games. Danny knows this. We all know this. Danny's not thinking any differently than many of us are. The edge Danny (and every team employee in every sport) has is information, not brainpower or strategy.
And I don't get where you toss in this notion of fans only looking at the "now". That's clearly not accurate for many fans.
The whole argument of free agents not wanting to come to Boston is unfounded. There is no clear evidence of this. Every single player is completely different in what they want / do not want.
To try to suggest that a teams rank / position in the league doesn't impact it's ability to attract free agents is...bewildering. Nobody wanted to go to Cleveland before they got Lebron and Love. Why? Because teams know that with Lebron / Irving / Love they are going to be a competitive team, and can offer a good chance at winning a title.
Sacramento has the best center in the NBA, but which big name free agents choose to go there? None. Because they don't win. If Sacramento finished last season with the 3rd seed in the West, watch how many players would have been scrambling this off season to try to have a chance to sign with the Kings and join Cousins.
Big free agents want money, and they want to win. If you can convince free agents that they are the missing piece to making your team in to a legit contended, and if you can offer them the pay cheque they want, then you will inevitably attract some number of free agents.
Right now we are a 7th seed, first round sweep exit. No free agent short of Lebron is going to (on his own) turn us into a contender. Our success last year helped give us a hope in speaking to free agents, but still makes it hard for us to actually get one to really buy in.
If we pick up a couple of small pieces, make a couple of small improvements, improve to a 3rd or 4th seed, win (at the very least) one first round series, then it changes that perception.
Plus yes, very few fans TRULY look past today. They do when it comes to players (i.e. get this guy because he has potential) but they rarely do in terms of deals (i.e. this could be the deal that later leads to that deal).
Most fans seem to look at things in terms of black and white - either we make a deep playoff run this year, or we tank and get a top draft pick this year, otherwise if we get either it's a wasted year.
What if this year is, in fact, a building block to a big next year? What if this year was the main target, but everything is being set up so that th e next two year are backup plans? Not many people seem to think that way - as in "if this year fails, what can we do next year".