When the IOC made the announcement, the International Ice Hockey Federation (IIHF) offering to cover up to $20 million in costs. The NHL didn't bite because there were other concerns as well. The Olympics forced a protracted break in the NHL season, the cancelation of the All-Star Game, and team owners had concerns about injuries to top players before the start of the playoff push. At the Sochi Games, New York Islanders star John Tavares was injured and missed the rest of the season.
"Quite frankly we don't see what the benefit is from the game standpoint or the League standpoint with respect to Olympic participation," NHL deputy commissioner Bill Daly said at the time of the announcement.
In a statement, the IOC noted it doesn't cover these kinds of costs for other commercial leagues, like the NBA. Though, the NHL faces the obstacle of a nearly three-week disruption of the season, which isn't an issue for the NBA during the Summer Games.