I'm not sure who they're arguing with here. Developers that write code in Ruby have a testing culture... I've never heard anyone imply that Matz and the core development team care even slightly about it.
In short, your average Ruby project and Ruby the project are entirely unrelated, they're written in different languages, even!
I took the line Hello, core Ruby developers! You've got an awesome language there. Could you start testing, please? Your community seems to do OK. Why not you? to suggest that the author of the post is fully aware that the Ruby Core team and the Community of Ruby Users are two separate things with different attitudes towards testing.
I agree with you, but if you get detailed, you might also question the use of "culture" as in "who has the testing culture again?" to be more indicative of Ruby developers as a community (which is a word the author also uses in praise of it)
I think the words were poorly chosen. I understand the main point, which IMO supports your assertion. But knowing the habits of people surfing the web, I can certainly understand how it doesn't appear that way to everyone.
I'm not sure who they're arguing with here. Developers that write code in Ruby have a testing culture... I've never heard anyone imply that Matz and the core development team care even slightly about it.
In short, your average Ruby project and Ruby the project are entirely unrelated, they're written in different languages, even!