I appreciate your feedback, you make some great points but there's an important detail that I realize I'm leaving out. The account you mention is actually part of a voting circle. Look at every post and comment and it's the exact same accounts voting, every single time. That's why this account is on my list, but I need to point that out a little more clearly.
A secondary point is that I'm not automatically downvoting these posts myself right now for exactly this reason. I want everyone to use their objective judgement to determine if they feel a post is worthy of a flag.
My larger mission is simply to remove the incentive for creating bad content. I appreciate your remarks about vigilante justice, but if you dig into my posts and comments you'll see clear evidence quite the contrary.
Maybe err more on the side of saying that something is not spam if it seems to be in a grey area.
I will always err on the side of protecting the rewards pool and the blockchain itself from the impact on bandwidth from superfluous comments. Any account that is producing legitimate content can easily recover from a few lost rewards and we have clearly seen that the community is happy to continue supporting actual content.