I agree that your comment had value and didn't deserve to be downvoted. That being said, I think you're jumping to too big of a conclusion based on a single (assuming it was only one) downvote - that HN has become a place where contrary opinions are squashed. Chances are good that someone simply isn't aware of the community standards as to when they are and when they are not supposed to downvote - that downvotes are meant to be reserved for when a comment adds no value to the conversation, not when one simply disagrees with the opinion being shared. In that case, the person needs to be educated to the community's expectations. But we should also not rule out the possibility that someone meant to upvote you and instead pressed the downvote button, which are entirely too close to one another, and of which there is no ability to reverse.

Or someone simply thought that the comment was jumping to conclusions with no real data about the actual cause of the problem.

Shipping problems are common enough that two instances close in time does not say anything about either seller, and even if one is bad is does not mean the other is.

Only over the last month I've have one package I ordered from an Amazon Marketplace seller get lost... by Amazon Logistics (first time ever I've seen Amazon's tracking show "package lost by carrier"), and another, from a Kickstarter project, stuck in DHL-limbo for 3 weeks - neither problem had anything to do with the sellers.

I thought only long-time members could downvote?

HN has pretty much always been a creepy echo chamber where more or less all posts toe the line of "whatever startups do must be right, so don't question or criticize".