down-voting is a community moderation tool, to be used on comments that are off-topic, trolling, spam, etc.
The article in question is about AirBnB's repsonse to the situation (or rather, about EJ's comments about their response to the situation). The comment you down voted is making a point about a possible reason they may be acting that way.
It's a direct and thoughtful response to the topic at hand, it's ipso facto "relevent" in the sense that matters re: down-voting.
The fact that you disagree with it, or think it is flawed is not a valid reason for down-voting; instead you would reply refuting their point. You seem to think that their comment is not "relevent" re: how one considers their actions...and that may be true...but that is not a valid reason to downvote and not the sort of relevance that matters re that.
I only bring this up because many people seem to be confused about down-voting, or abuse the system and I think it's helpful to have a dialog on it occasionally.
Edit: To add how good it was to see someone explain a downvote, so we could continue a discussion.
Criticism sucks, but with a company like Airbnb that's the deal, and the founders knew it from the get go. This is the price (one of many) they pay for their eventual big payday. Overall, it's a pretty good deal though =)
"Screw clients, acquire currency!"