I wish the article put actual numbers or evidence of declining sales. I agree that reduction of sales is the most likely cause, but if they say that sales plummet without actual proof it becomes poor journalism.
It's not you, it's just that we've allowed "journalists" to get away with this for so long. They essentially write opinion pieces as new articles with absolutely no research. : Synology is a private company, so I guess they can't use stock filings or stock prices, but they should at least quote something substantial and add to the discussion.