IMO a sport must have 3 criteria:
- It must be a competitive
- It must be a game (a game must have a point system and a defense for my criteria of a sport)
- It must be athletic
Poker fore example is both competitive and a game, but it is not athletic
Things like skiing, gymnastics, and running (I am an avid expert skier BTW) are athletic and can be competitive, but it is not a game (as there no defense)
Fishing is not a sport because it is not athletic and most of the time it is not a game. I know they do have competitive fishing, but it is still not athletic.
I can see the argument for golf going both ways. I do play golf, just as I ski, but although golf is less athletic than skiing it is more of a sport than skiing, IMO. Golf is someone athletic, it is a game, there is scoring, but it does lack defense.