Why does the indirect quotation (ㄴ/는)다고 mean "just because" in the following cases?

Question

I have studied grammar (ㄴ/는)다고 before and know that this grammar is indirect quotation in Korean, which means "to say that/to ask that....". However, today I learned again that this grammar also means "just because", for example in the following example sentences:

네가 똑똑하다고 항상 맞는 게 아냐! Just because you’re smart it doesn’t mean you’re always right

가난하다고 저를 무시하지 마세요. Don’t look down on me just because I’m poor

I wonder why this indirect quote means "just because"? When I apply the meaning of "다고(that)" to the sentences above, I find it difficult to understand them as "just because". Can you explain for me? Thank you!

Answer 1

-다고 is the quoting suffix as you said, but your examples are using it in a different sense. It is a short form for -다고 해서, where 해서 makes a clause to be contradicted in the main clause, like "just because ... (it doesn't mean ...)" you mentioned. In this usage, the original sense of quoting is almost gone other than that it highlights a fact just to contradict it for the sake of argument.

네가 똑똑하다고 항상 맞는 게 아냐! = 네가 똑똑하다고 해서 항상 맞는 게 아냐!
가난하다고 저를 무시하지 마세요 = 가난하다고 해서 저를 무시하지 마세요.
나는 고기를 좋아하지 않는다. 그렇다고 (해서) 전혀 안 먹는 건 아니다.

-다고 해서 can also mean simple quoting without the contradiction, but in this usage we contract it to -대서. So -다고 and -대서 are two shortened forms with different functions.

영철이한테 같이 가자고 했는데 싫대서 나 혼자 갈 거야.

Here 싫대서 is short for 싫다고 해서 but it is a simple quote of what 영철 said (싫다/싫어) with no sense of "just because".