I personally view losing to save a protected draft pick after a certain point of the season a bit different than going into the season with the complete intention of losing as many games as possible. The year of the warriors I think they tried very hard to be competitive and win games for the first 50 games, realize they didn't have the horses and then stopped trying. Although the Heat did not really do this this year, I wouldn't have really held it against them if they lost their last 3 games intentionally to ensure that they didn't lose the number 11th pick in the draft. I think at those levels it is just smart business, but this is clearly a slippery slope.
The bigger thing is the NBA needs to eliminate protected picks. Teams need to either trade first round picks or not. A system where a team can either have a top 4 pick or lose the pick completely creates so much more incentives for teams to tank than a team that might just get 5th instead of 4th. I do wish the NBA would fix that.