This trade on its own makes no sense for Boston...they basically gave up Crawford and Brooks for nothing. All they get back is Joel Anthony (who is crap and is owed the same money) and two (likely second round) draft picks.
I am assuming this deal was made to make room for a bigger deal - most likely that Danny needed either roster spaces, draft picks or a guy on a $3M contract (or all three) to make the next deal work.
Either that or Danny made the trade to purposely make the team worse in the hope of losing more games and getting the worst record possible for the draft.
Tanking or prelude for another deal would be the only two explainations that make any sense for Boston.
Calm down. This deal makes plenty of sense. First of all, Crawford was not that wanted. GSW gave up Toney Douglass for him. Miami could have had Crawford, but preferred to pay less money and get Douglass. Last year, Danny got him for nothing. No protected second-rounder. Not even a trade exception to Washington. Just two vet min expiring contracts, one of whom was out for the year. That's it. Crawford is not a very valuable player.
Second of all, Boston gets one of the following:
1) A first-round pick this year or next year, likely to be in the 15-20 range, and a 2nd rounder in 2016.
OR
2) A 2nd rounder in 2015, which is guaranteed to be early in the round, as otherwise Philly would have had a good enough record to give up a first, and TWO second rounders in 2016.
They got this for a player who last year no one wanted, who this summer no one wanted, and this off-season will not be given a qualifying offer. They got this because they were willing to take on $3.8 million in salary from the Heat, some of which they're getting paid back for.
As I've said already in this thread, Boston's goal this offseason is to sign a free agent through a sign-and-trade, or to get a good player from a team that is looking to shed salary/rebuild themselves. To do this, they need two things: draft picks, and expiring contracts in 2015. They got both of those in this trade, for someone they didn't want and no one else did all that much either. And if they don't succeed at making a trade this offseason, they still acquired draft picks, potentially one that can be as good as #15 overall next year.
At worst it was an okay trade for Boston. Depending what comes of either the Philly draft pick or what they're able to flip it for, it has the potential to be much better.