"You" refers to people in general. What kind of logic is behind it?

[Ov28]

I know "You" can mean people in general.
What I'd like to know here is the logic behind it.
Why have the second personal prononun implied general people?

Thanks in advance.

[AstroNox]

The second personal pronoun came from two Early Modern English words: "thou" and "ye". "Thou" was singular and "ye", plural. They have now been replaced by that one word "you" and that's probably how this came to be.

What I interpret from you saying "people in general" is probably in such a case:

(in reply to a friend who just told me the fallacy another friend made) "Yeah, I know what you mean. Bob was wrong to have done that. You can't just give someone your hard-earned money just because he claims to be your long-lost brother..."

The first "you" in the first sentence refers to my friend.
The "you"'s and the "your"'s in the third sentence refers to people in general and definitely not my friend.