If it "emphasizes that something is a natural result", then how could it be omitted, since omitting it would remove that emphasis and thereby change the meaning of the sentence?
– Jun 28 '15 at 18:26
Yes. I should explain a little bit more. Even if it is omitted, we can still make natural sentences (without meaning of emphasis). Ex. 彼はあまりにできるからヘッドハンターの目に留まった。/彼はメールを受け取らなかった/あの地震にも耐えて残った/そういうことだ/
– user51966Jun 28 '15 at 22:35