Cockroaches thrive in the dark corners. Sunlight is antiseptic. And forcing ideas/speech into those dark corners don't keep them from growing, it merely allows it to grow unobserved and un-countered. Ideas are the only counter to other ideas and how we communicate those idea is via speech. Suppression only invites martyrdom on the behalf of those suppressed, increasing their credibility.
The question is, should "bad speech" be amplified, promoted, propogated, broadcast, surfaced, and repeated, ON PURPOSE; just so it can get rebuked, debunked, dismissed, and exposed?
(I agree with you, the answer is closer to "The Remedy to Bad Speech is More Speech ... Marketplace of Ideas" however, the question being discussed is more akin to "Theres a limited amout of space at the front page, and people have limited amounts of attention to give, WHO gets the megaphone, and for how long". Its the inverse of "the robust debate principle recognizes that sometimes in a crowd of speakers it is necessary to turn down the volume of certain loud and clamorous speakers in order to give others a chance to speak." Facebook and the algorithm DO DECIDE who to turn the volumn up on, who to promote to the top. They already arent neutral, they already exhibit preference and bias for certain ideas.)
Others are arguing that this is flipping the argument, BUT we are talking about algorithmic placement moreso than true censorship. If someone is allowed to post something but it NEVER makes it into someone elses Newsfeed, is it as good as censored?