Why is の used here instead of こと?

Question

On a grammar website (that tries to use somewhat more literal translations) I came across this sentence:

彼が出席しなかったというのは、よほどのことがあったんだろうね。

The fact that he did not attend must mean that there were inordinate circumstances.

It is my understanding that というのは is used more for subjective conclusions and interpretations, like perhaps “the fact that he has been calling you recently is odd” rather than a sentence like “the fact that he hasn’t arrived yet must mean he got caught in traffic” which sounds more objective and I would expect ということは.

In fact putting the translation of the original sentence into DeepL yields the exact same JP sentence but with こと instead of の. I know の can stand in for こと as well sometimes but it also can sound more subjective. Is this a case where either is natural, or is there some other nuance at play, perhaps because of the んだろう at the end?

Answer 1

In this particular example, replacing の with こと doesn't change the meaning much.

彼が出席しなかったということは、よほどのことがあったんだろうね。

Because of という, however, this sounds like the speaker is trying to logically draw some conclusion based on what they have learned.

Removing という results in an unnatural sentence.

[x] 彼が出席しなかったことは、よほどのことがあったんだろうね。

Also, ということ sounds weird if the main clause is merely the speaker's impression.

[x] 彼が出席しなかったということは、珍しいね。

It's hard to pinpoint what exactly the の in the original sentence refers to. I would understand it as the whole circumstances that led to his absence, rather than (just) the objective fact that he didn't attend.

彼が出席しなかったというのは、よほどのことがあったんだろうね。

という is totally optional.

彼が出席しなかったのは、よほどのことがあったんだろうね。

The following sentence is also fine.

彼が出席しなかったというのは、珍しいね。