This is arguably the most ridiculous tradition in American professional sports. Yes, the owner invested the money in the organization, but it's the players who won the championship.
As is the case in soccer and many other sports, the team captain is the first person to lift the trophy, and rightly so. Having the owner come down from his luxury box, put on the mandatory hat and awkwardly raise the trophy just doesn't sit well with most fans.
The worst example of this tradition occurred in 2009, after the Lakers beat the Magic to win the Larry O' Brien trophy. Anyone who watches the cringe-worthy video above (Joey Buss, a 19-year-old rich kid, accepting the trophy), and says that's the way the presentations should be carried out, clearly is not a real sports fan.
Joey Buss, the owner's son, had no impact on the Lakers' victory, and therefore should not have the privilege of accepting the trophy.
P.S.: The last 15 seconds of Joey's acceptance speech are just painful to watch.