It might seem that way, but in practice it works out that the inconsiderate party is the person who is in every thread attempting to dictate when everyone else can discuss a live event. A sporting event is very different to movies or TV, the consumption of those is always staggered. Sport is a real thing that exists in the world and happens in real time and gets discussed as such. You might as well jump into a thread and say "Guys, don't discuss the election results! I've taped it and will watch it next week!". Sports are more analogous to that than a book.
First off, my comment to rep was said jokingly, just in case people think I'm being a spoiler nazi, which I'm not. I don't particularly care that much. I just wish people showed a little bit more consideration to others that may not consume media immediately due to other commitments.
Having said that, what's the difference between watching a sporting event on TV and watching TV as it's first being aired? Surely if most people are interested in watching Game of Thrones they should have probably watched it as it was broadcast? I don't see why a weekly event that is filmed live should get special consideration over something that was pre-recorded and shown on television on the same schedule.
Also, most media has quite a similar consumption period than sport; granted, sport does have a far more truncated consumption period. The largest concentration of people watch movies on the first weekend. Most people will usually watch a television program in the same week it was released. Video games get bought close to release, especially in Japan where most of their sales are in the first week.
As it stands, I'm not dictating when or where people discuss things, I'm just saying that not enough people show consideration when rushing to talk about books/movies/sports. It's the reason why forums have dedicated threads so that people can freely discuss matters without affecting those that are not ready to discuss those things.
But, I don't want this to become a huge discussion when I made an offhand, joking response to rep. My apologies if any comment came across as seemingly dictating where people can discuss matters.