even an exceptionally dumb thing for someone on the internet to profess belief in.

Wrong reference class, "someone on the internet", much too broad. Just as your comment shouldn't usefully be called an exceptionally smart thing for a mammal to say, we should refer to the most applicable reference class -- "someone on LW" -- which screens for most simple "haha, that guy is clearly dumb, damn I'm so smart figuring that out" gotcha moments. Shift gears.

The original comment was close to "we'll need quantum and/xor quarks to explain qualia (qualai?)." Not exactly subtle with the "xor" ...

I'd really want to know this (no need to pay the karma penalty, just PM or edit your comment): Did you really take the comment at face value? This was the intent of the comment pre-edit.

It may be interesting if that's a cultural boundaries thing for humor, or if LW'ers just keep an unusually open mind and are ready to accept others to hold outlandish positions.

Actually, its content has not changed, what has changed is how the content is presented. Note how "quantum computing", or quantum this or that, is usually brought up like a mystifying secret ingredient to e.g. consciousness/qualia (Penrose) or any other property that some would rather see remain mystic. Quantum computing actually is a thing, but an "AI is unfeasible until we do quantum x" just pattern matches too well to arbitrary mystic roadblocks.

Since the point was lost with the humor apparently either disliked or taken at face value, I've decided to edit the comment such that the same point is made, in clearer presentation, so that those that just skim comments (and their vote counts) and are quick to judge before parsing are accommodated as well.