The takeaway from this particular story is that a binary choice--tanking or not tanking--is insufficient to describe the decision-making of NBA teams, all of whom are at dramatically different points in the success cycle. In every choice they make, teams must balance success in the immediate future with their long-term goals. This is true in every sport, of course, but especially so in one with a restrictive salary cap. Spending money and other resources on players who help win games now means paying the alternative cost of sacrificing the development of other, younger players who could be more effective in the long run.
Toronto was "aggressively rebuilding"....
I find something more rewarding about watching young players lose games than seeing veterans clearly heading nowhere. These rookies and prospects, no matter how promising they really are, represent some kind of hope for the future. As I've often borrowed from USC coach Kevin O'Neill and repeated in this space, NBA teams are either selling wins or they're selling hope. Taking that hope, in the form of lottery picks, from losing teams would be crushing to their ability to keep fans engaged.
From that standpoint, I find aggressive rebuilding to be a victimless crime and a crucial part of managing a team. Tanking is more sinister, in that it robs the rest of the league of the level playing field we expect and demand, especially during a playoff race. I just don't think it's that common in the NBA outside of seasons, like 2006-07, when the top of the draft is considered exceptionally strong.