I don't think Poe's law is applicable here on HN/anymore in general. Writing something stupid is not as valuable/funny as it was in 2005. The lack of /s or /j is only one half of the problem, the other half is that that comment is garbage. (I estimate these two are ~50-50% problematic in this case.)

I think a better rule of thumb is that one shouldn't use tone indicators at all. If you are needing them, then chances are that what you are going to post is not valuable/funny.