Pretty much everyone accepts that absent extraordinary circumstances, you need a franchise player to win a title in the NBA. The way I see it, there are three ways to acquire this player.
A. The "disgruntled star" method
Stockpile assets and wait for the next available franchise player that becomes available on the trade market.
Ex) KG, Ray Allen
B. The "one guy away" method
Become an attractive team with one superstar already in place and a core of good young players while still maintaining exactly a max-level contract's worth of cap flexibility. Sign a superstar who wants to win a title in free agency and wants a team with a supporting cast already in place.
Ex) Dwight Howard to Houston
C. The "win the lottery" method
Draft a superstar. There are some exceptional cases where a team strikes lucky on a pick they traded for (hopefully us with the Nets pick) or a superstar is drafted way later than he should be (Rondo or Paul George), for the vast majority of teams, this will require tanking hard for a top 3 pick.
Now method A is obvious. Anyone doing any semblance of a competent rebuilding job should be focused on constantly increasing the value of assets in hand in case a superstar becomes available.
But for the most part, methods B and C are mutually exclusive. One requires you to make a deliberate effort to get better, the other requires a deliberate effort to be worse. Therefore, rebuilding teams need to make a choice: they either go for AB, or they go for AC.
Obviously, nobody likes losing games and seeing their teams get worse, so B is more attractive than C. Why do so many teams choose C then? Because not everyone has the talent available to become a "one player away" team, and if everyone is trying to be better and win games, obviously it's trivially easy to be worse and lose more. Teams choose tanking because it's easier.
During the pre-season, everyone thought we were a team that was going for route C. The players we had weren't anywhere near good enough to build us into a 'one guy away' team, and a lottery pick in a loaded draft looked like the best option available.
But two things have changed: one, we're a lot better than we thought. Two, its' no longer true that being worse is easier than being better. So many teams are actively trying to tank (or are just really bad at basketball) that it's got to the point that trying to be competitive might actually be the 'quick fix.'
I think players like Sullinger, Green, Bass, Crawford, Lee, and Bradley have proved that they could be very strong complementary players. We already have one superstar in Rondo. If we can net Asik without giving up too much, we pretty much have an entire supporting cast already in place, waiting for that one final piece, especially if these players prove themselves with a decent playoff run. The way I see it, us with Asik would be just as attractive a proposition as pre-Dwight Houston. All we need is to wait for some contracts to expire.
At this point, getting better may actually be the easiest way out, not getting worse. We're not realistically going to be able to out-tank teams that are hellbent on the lottery no matter how many good role-players we trade away for nothing. The strategy that gives us the best chance of netting a superstar is getting as good as we can while waiting for contracts to expire to leave a hole in our salary cap that one max-level player can fill.
Winning just feels better. If winning is now easier than losing, why not try to win?