I totally agree with you about

Those that are not great at doing this and answer with Thanks! are not much better than those who comment with Nice post! are they?
However, I couldn't understand that nobody get upvote to unknown people. There is ecosystem or community who always get upvote to each other.

I am the newbie in steemit and I am working on generating good contents especially funny gifs. But, nobody upvote and resteem. This means I never grow up.
There are so many people like spam. I hate them but people who work too much on steemit getting nothing, disappointed and do these things.