You know it is possible for this team to have been significantly luckier than last year AND also be a better team. Those aren't mutually exclusive.
I also don't buy into the idea that this team just hates to lose or knows how to win close games any more than teams in the past. Does anyone really think that basically the same group of guys who were bad last year at this particular part of the game just happened to figure it out now?
And I think a lot of the pushback vs "luck" is rooted in that most people are really bothered by the word and concept of "luck" in a lot of situations and don't truly realize just how much randomness impacts our lives, success, failures, etc.
Acknowledging how many external factors outside of one's own control play a huge role is humbling and it comes into play in sports, business, life, etc
Reading the Drunkard's Walk by Leonard Mlodinow might open some eyes.