Because you're confused with "论点". I'm trying to tell you a "论点", or argumentation, is the main point you want to make in your essay. To proof it, you need evidence, and reasoning (proof the argumentation with evidence).
But a simple fact is just a simple fact to the essay. You can't say, hey, this is the argumentation. You're missing the (main) point.
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又在玩文字游戏!?不过别人都替你解围了,我也没什么可多说的....就一句话你从头到底没有回答过我的质疑...:p