I suspect you received down votes because your initial comment comes off as dismissive. A lot of HN members tend towards encouraging constructive criticism rather than only pointing out limitations (especially for Show HNs† which this effectively is) in the interest of facilitating a civil forum. Given the limitations of text (particularly online), it's easy to misinterpret tone. I think you could have said essentially the same thing with some simple rephrasing. For example:
> "I think this is likely a useful exercise. That said, I'm not sure I see myself actually using this."
> "We already have web server..."
Yeah, it's subtle, but I think it comes off differently as it's more upfront that doing this may actually have had a use. And both the writer and the reader are involved in the communication: you yourself can only control so much.
https://news.ycombinator.com/newsguidelines.html