First, my sincere gratitude, @timcliff for trying to think out a way of discouraging spam within the platform. A lot is obviously desired, technical-wise. Let me just quickly pass my thoughts. I will straight away start from where your proposed idea concludes

If we increased this threshold up to 0.10 SBD, or even 0.25 or 1.00 SBD - then posts/comments that did not receive sufficient votes to pass this threshold would receive zero payout. This would likely decrease the incentive for users to create spam.

But going by what we currently know, who otherwise upvote and reward those ‘spam’ comments? Two categories, one, the spammer himself and two, the community.

Granted, the community will not upvote any such spam comment, and even if a few do, it will not pass the set threshold to qualify for payout. Goal achieved!

But how does that discourage the high Steem power spammer who will upvote his own spam comment above the set threshold so to still qualify for payout?

Do you know why the posts of people with High steem power comparatively get the most upvotes and the most comments as well? Putting aside the issue of upvotes, people comment because they hope, or indeed, scheme to get an upvote on their comments by the high steem power post author.

Make a good comment, and you get rewarded with a high reward upvote. Silently, and there is nothing we can do about this one, low steem power accounts are disenfranchised. Why should I spend my time and energy commenting on your blog, when the most your 100% vote can give me is 0.01$? This is what the reward schemer asks, and many are. It after all isthe end, largely about rewards, no?

But of course not everyone is like that, and some people still visit and take time to comment on posts by low Steempower authors, incentivized even with the likelihood of that 0.01$, and if on a good day, accumulated to more from other peoples collective upvotes.

Do you see the point I am driving at?

The threshold to qualify for payout that you here propose would be way above what several people’s 100% upvote gives. The problem, which hopefully I have built up to satisfactorily, is that people will only be further discouraged from commenting on the posts of those whose 100% upvote moreover does not at the end of the week qualify to pay out. I mean, why should I anyway?

Setting the threshold as you so suggest, may to some extent discourage spammers, but it would do so at the expense of further disenfranchising the low steem power accounts from meaningful engagement by the community on their posts.

Moreover, going by this threshold line of reasoning, it would equally seem plausible to suggest that we set a threshold for rewards payout on posts, in order to discourage shit posts! Do you see where we would be headed?