Here on Stack Exchange we're encouraged to be nice, but I feel like the canned messages from mods and from the system aren't setting a good example in this regard.
Example 1
Comments are not for extended discussion; this conversation has been moved to chat.
This message is direct and impersonal to the point of rudeness. It isn't really an explanation; it's a rebuke.
Example 2
closed as primarily opinion-based by [users] [date] at [time]
Many good questions generate some degree of opinion based on expert experience, but answers to this question will tend to be almost entirely based on opinions, rather than facts, references, or specific expertise.
If this question can be reworded to fit the rules in the help center, please edit the question.
This isn't as rude as the comment message, but it's pretty impersonal, especially with the passive voice in the last sentence. It could be more polite.
Maybe there are better examples than the above two. I'm proposing we have the discussion. Are we encouraging politeness with mod messages and system messages? Can we do better?
EDIT
A good example of a company choosing friendliness over, we might say, succinct communication, is the Slack release notes. They could say
Improved look and feel of HTML notifications.
Instead, they say
We've changed the look, feel and texture of our new HTML notifications. Give them a try! They're delicious.
The second is longer, to be sure. It's also friendlier and more entertaining to read, and I'll bet a lot more people read the release notes of Slack than the release notes of software that uses the first style. These release notes have a personality.