Most of the time open source tools are a labor of love. If the tool is not for you, move on. But self-aggrandizing "this tool is not good enough for me" posts, when you have not contributed, and when you disregard the fact that the tool has been immensely helpful to many others (who might have even started contributing back) just creates negativity in the world for no good reason. Nothing good is created in posts like that (and no, such posts are not constructive critique).
And then there are "the language is dying" complaints -- I consider these the worst of all. A tool does not need to be the most popular tool to be useful. Let's stop chasing hockey-stick curves in all human endeavors.
(to prevent claims of sour grapes: I am not a Scala user, I just find this type of posts distasteful, no matter the target)