So, the put it more clearly: You are all complaining about ....nothing
Get a degree.
Actually, you are quite incorrect. Although I agree port 0 is officially not a supported port, it can be pinged as can port 1, regardless of port 1 being a multiplexer port. That means that a hacker can potentially verify you have a router at a give IP address when it gets a "Closed" status back instead of no status (stealth).
You can argue that there is nothing a hacker can do with the ports closed but I prefer to not let hackers, whom are much, much more knowledgeable and determined than I am, to not even know my router exists.
It's a simple concept. I don't understand why D-Link doesn't get it or just doesn't care.
Put another way, even if it is not a serious issue, from a pure business perspective, D-Link management are foolish to no implement this because of all the complaints over the past two years and the fact that their major competitors all implement this. What more logic do you need?