Before the age of videos and dedicated boss pages, boss kill strategy was extremely elusive. We're talking back during the vanilla era of Warcraft. The time it took for guilds to crush bosses took weeks (sometimes months). The top-end 40-player raiding guilds all consisted of the best that the game had to offer. Guilds below them had a player consistency involving 10 really good players, 25 mediocre ones, and five AFK raiders.
How did those players learn? Who did they get their strat videos from? With no Encounter Journal, everything was done from a trial-and-error standpoint. The general plan for healers in these pioneer raid teams? Heal all the things. Eight to 12 healers were used (at least, when I did them) for learning. It was a race to see if we could stay alive long enough to destroy raid bosses. Some of the bosses in Blackwing Lair took 20-30 minutes.
Fast forward years later, and now we have all these different tools at our disposal. There are videos and the attached commentary that walks players through what happens on select stages of an encounter. Blizzard itself has provided a database of abilities within the game. Walk-throughs are littered across the internet on major information sites, blogs, and forums. Rarely is there ever a unique strategy to a boss, because we watch the pros undergo various attempts with different approaches. Sometimes they work; sometimes they don't. Eventually, they settle on a method that delivers constant kills. That information gets released and filtered down to the rest of us, which we then adapt ourselves.
Originality isn't exactly common anymore.