The Merit system was introduced to reduce spam, including spam from account farmers. What you're proposing would give account farmers all the sMerit they need to rank up by spamming, and I don't think anyone wants to go back there.
What if the community decides Legendary members get sMerit based on recent six month activity? How does that give account farmers the sMerit they need to rank up by spamming? No one wants to go back there, but we need an overhaul. Suggest something.
I agree Theymos should test something different like this one because what I see these days is smerit distribution isn't fair. I saw many helpful posts, but they ignore them(Bias is real).
About spamming, it's already reduced after the merit system was introduced, but the distribution of merit seems based on bias or favoritism.
Why not try this for, I think, 6 months or 3? Let's see how spammers would be able to spam.
And honestly, what's the purpose of the report button if the whole forum is totally clean from spamming?