Josh acknowledges that people do actually use this staircase in both directions. If they really meant to only go down, the direction to stay right would make less sense, in fact. Which leads to my next question: why post the sign at all?
I don't usually post the following: newspaper headlines, personal email, craigslist postings, unprofessional websites. I also tend to not crosspost things from other blogs, since I have so much unique material waiting for me to get to it.
Things I see a lot: silica gel "do not eat"; hair dryer labels; inside the bus "do not drill"; Wal-mart sign about IDs; coffee machine with "2" cup sizes; employees must "wash hands".