> "What's the points of this? I've been doing the same thing since the 80s by piping four shell commands together?!?" - is not really constructive.
> Letting people know you are unlikely to use the code/product/gizmo is also constructive, especially if you can manage to tell why.
By my reading, these two statements contradict each other. The quote you claim is not constructive seems to me to be saying the author sees no value in the hypothetical contribution, as it offers no additional power and less convenience than what he already uses, and therefore he won't be using it. Isn't that exactly what say is constructive in the second statement I quoted? If I'm misunderstanding you here, can you explain what I'm missing?
That first example was from a specific thread that actually happened when someone made a command-line tool, and the whole discussion was incredibly unproductive and full of "look at me, I solved this eons ago, this developer sucks" messages. You're probably right there is a fine line between those two, but they are not identical. It's the difference between saying why you wouldn't necessarily use something on the one hand, and showing off while berating someone on the other.
Asserting that a project's existence is unjustified is a bold and unfriendly claim. Saying that it's simly not for you is another matter entirely.
As an example, this would be a constructive way of saying something similar in my opinion, though some may still find it close to the line:
"I have found my own solution to this problem that involves piping these commands together, so this project isn't for me, but good job for creating a simpler solution for people who don't necessarily need control over every step of the solution, but rather just care about the final result."
This indicates why it's not useful for the poster, but it acknowledges that not everyone is a CLI genius and that the new solution could work for people with different tools requirements.
> Letting people know you are unlikely to use the code/product/gizmo is also constructive, especially if you can manage to tell why.
By my reading, these two statements contradict each other. The quote you claim is not constructive seems to me to be saying the author sees no value in the hypothetical contribution, as it offers no additional power and less convenience than what he already uses, and therefore he won't be using it. Isn't that exactly what say is constructive in the second statement I quoted? If I'm misunderstanding you here, can you explain what I'm missing?