To put it another way, true tanking requires both intent and forethought. Just because you're bad, just because you're losing, doesn't mean you're tanking. The Suns, current record notwithstanding, are tanking: they traded their starting, borderline All-Star center, and their sixth man for a guy who might not play all year, a guy they knew was not going to play, and a draft pick. That's tanking. The Sixers traded an All-Star for the draft rights to a guy they don't plan to play all season, healthy or not; that's tanking.
We're not set up to be able to do that, so we might as well play to win, and let the ping pong balls fall where they may.