And all this tanking "argumentation" (parroting) like it's "the only chance", it's not only "the only chance", but tanking has in fact a pretty bad chance, less then 5% of all teams that tanked ended up getting a championship out of it and no amount of (repeated) arguments will change those facts.
In fact, no choice whatsoever is "the only chance". But some choices give us the best bang for our buck. No matter what we do, odds are we don't win a title in the next 10 years because there are already transcendent players in the league and they aren't on our team.
And your 5% number is just made up. But that doesn't matter. Because San Antonio was rewarded with multiple titles for tanking.
On a side note, how many championships over the last 20 years had a #1 pick at the core of the teams success? How many titles do Duncan, Shaq and Lebron have? How many teams have made it to the finals on the back of #1 picks, though they eventually lost? We have Duncan, Shaq and Lebron again, along with Howard. If we add #2 picks, we may see quite a few more Lebron and Durant appearances in the finals.
The whole taking discussion is moot. We have our team. The team is going to play hard no matter who is in the draft. If Danny Ainge feels that long term, trading a player who contributes this season for someone who will contribute even more in 2 seasons (though perhaps not now), he might make that trade. You might call it tanking. Whatever. All it is is a GM having a plan to prepare the team to be good in a few years and accumulating the assets that can contribute then. Ainge's moves will likely be limited by his desire to not completely alienate the fanbase, so we won't see moves where he ships out talent for nothing. But we will see value now traded for expected value later.