All you are doing is playing with words, while ignoring the essence of the thing itself. We all know what a playoff is, it is multiple teams playing in order to reach quarter finals, semifinals and then the finals. In some cases this is subdivided further or to a lesser degree. However in general knowledge terms a playoff is not 2 teams playing in a final. It's a cute play on words and misdirected logic your using, but that's all it is.
All you are doing is spreading a misconception. Playoffs can exist with any number of teams but 1. Any post-season, championship-determining game, or series of games, is a playoff. The two best teams "play off" for a title. That's where the term originated. To say that I'm the one contorting it is completely off base. Fans may use the term to reference a specific style of postseason (same style, just bigger), but it means the same thing as it did initially. I've given a dictionary definition, outlined the logic I used (and you can too!), given hypothetical as well as real world examples. You can't just say I'm wrong and you're right because you feel like being right. "We all know what a playoff is" is not an argument. In fact, as you and several others have proven, it's absolutely untrue.