Good points @leebaong, overall flagging is very misunderstood. Because most users talk purely about upvotes and the rewards, which makes it much harder to have a balanced conversation about flagging (an equally important feature of the Steem blockchain).
Lot's of flagging is subjective, but it will probably evolve just as this platform evolves.
I actually somewhat favor the act of flagging. I've seen a lot of generic comments which sometimes irritates my stillness. I'm just afraid of the subjective abuse! Though thanks to the community, I've never been flagged yet. Hopefully, will never be.
Openness though still lives in me. One reason why I love steemit is I learned a lot of ideas and I'm open for it. Development needs conflict of ideas to come up with a strong outcome.