It's not so simple.
There is a responsability towards the aikido people who still have not the ability to discern what is reliable information and what is bs. If bs remains unadressed, silence means assent.
OTOH, I would not like to see downvoting posts as an alternative to debate. Mob justice, censorship and anonymous bandwagoning are no substitutes for discussion.
I don't know man, I disagree. It seems the problems are:
1. People posting BS (subjective)
2. The debate surrounding said BS
3. People wanting proof in some form to verify if the BS is really BS or not.
1 and 2 are what they are. If it's BS you call it BS, respond to any meaningful follow-up and you leave it at that, move along. It doesn't have to devolve into 16 page long threads full of back and forth nonsense that goes nowhere. When it comes to 3, if you ask and aren't obliged, then you just file it as BS and move on. You've had your say, you've tried to advance the facts, anyone who comes along reading it is going to see what took place and make their judgments. I'm not here to shepherd the masses through the valley of evil. If someone is doing something (aikido or "real life") and they're accepting it at face value, not researching, questioning and thinking for themselves, that's on them, not me. You will not change anyones opinion who doesn't want to let it be changed. That's a fact driven home by the internet every second of the day. So beyond doing the above, what more do you do?
Also, most of the vote systems like I referenced are obviously configurable. You don't configure them so that 4-5 downvotes are going to k-line every post. You set it so that the number represents a significant enough of a portion of your viewership to matter, but not be controlled by one faction. Also, most of them don't delete posts, they just hide the text of the post saying it's been downvoted "click here to view anyway". So people can still see a post that enough people though was BS enough to warrant the post being blackholed if they want to. These systems work fine and I've yet to see blackholed posts that weren't complete crap. It's not uncommon to see someone post their own followup when being downvoted to better clarify what they wanted to say. I find them fairly self-correcting.