KD was the best player in the league at a time. Disgruntled, hypocritical, and simple minded fans don't want to accept it because they base things off feelings instead of facts.
KD was close to signing with the Celtics in 2016, and if he did they'd have a dynasty. Imagine a starting lineup of KD, Isaiah, Horford, Jaylen and Tatum, with Marcus Smart and Jae Crawder from the bench. Isaiah wouldn't get injured (at least not that badly) because he wouldn't have all the load on him. I think they'd win 3-5 rings, giving KD a case for #2 all time, but not greater than Jordan.