The Dallas Mavericks very publicly made the decision to tank the last two games of the season. Because they made that decision so publicly and decided to talk about it so transparently, they were fined $750,000. A lot has been made of the decision to tank and whether or not it was some affront to basketball that guarantees negative basketball karma.
It was the right decision, and it absolutely does not guarantee bad karma. The San Antonio Spurs dynasty was built on tanking for Tim Duncan. The Houston Rockets tanked for Hakeem Olajuwon.