Noun

Thing refers back to it. For more context, you'll have to refer to the preceding sentences.

CSnyderThing refers back to it

I know it refers to it , Its combination with the word independence is kind of weird to me, what's difference in the meaning between independent or independence thing?Is is possible to say independence functions as independent here at least in the meaning??

When people say "It's a(n) [x] thing", typically what they mean is that what they're describing is either a step taken to ensure x or a direct consequence of x. In this case, someone might have said something like "I don't like to take money from others. It's an independence thing", which would could actually indicate the first case, the second case, or both cases simultaneously. That is,