Yes, I agree that improper flagging is a threat to the system and you did the right thing by retaliating with more downvoting. But more than downvoting, I fear the capitalist economy system here. If I had a large sum of money, I could flag all posts here and upvote all my and my fam's content to earn all the rewards on offer! The two most objectionable things I find here are:
Anyone with deep pockets can purchase a lot of Steem Power and interfere the reward system here by upvoting or downvoting any content. However I agree that investment into the system do give some value to the Steem but investors should not be given any voting rights on the content platform. They can earn the interest and speculate on Steem's appreciation or downfall. But should keep away from judging the quality of the content.
Even if someone haven't got very deep pockets then too he / she can upvote / flag any content by purchasing the whale power from certain bots. All these bots who vote merely in return of money are bane to this system.
In fact, I was mulling over flagging the very content being cited as an example in the OP but I didn't. Infact I requested one of my friends to upvote my comment there. Unfortunately, we don't have any significant SP to make any difference. And I thought probably, the 4 upvotes were 50 times more valuable than my voting power so my downvoting wouldn't have made any difference.
I haven't flagged any one so far. I believe flagging is an offensive action and would invite retaliation from the one who receives a flag. It's like a war ...and wars can never establish peace. So if @dantheman thinks flagging has some important role here and is a must then we need to develop more prudent system here. Flagging should be like nuclear bombs. No single person controls the nuke system. Some sort of consensual model should be devised for flagging.
It's easy for whales to think flagging is necessary. THERE IS NO CENTRALIZED AUTHORITY FOR STEEM. Therefore, "flagging" is useless. @dantheman didn't think this part through, unless he intentionally wanted initial coin holders to be able to silence others--after all, large whales or large initial coin holders can be paid to silence others. It's valuable!