After their huge Cloudbleed issue with the addition of this one, they continue to call out everyone through their blog posts. And everyone seems fine with it because they are a hype company.
What they are criticising however are things like not adopting new protocols or not taking things that affects everyone seriously. This isn't something that would happen if people were trying. And the response from some of the industry is "we know what we are doing", and shortly after the same thing happens again and again and again.
So I don't really see CloudFlare being that arrogant, if anything it's the "you are not better than us" from some parts of the industry that is. The day I see CloudFlare not trying I would be happy calling them arrogant. But if anything I would caution that they are too successful by trying more than most.
Cloudflare improved a lot. You can see just from what they're open sourcing that the usage of go and rust increased significantly. And I'm sure we'll notice improvements in deployment practices.
When Cloudbleed happened I was very vocal and skeptical, but this is different. Everyone makes mistakes.
You say this like using trendy languages implicitly indicates improvement.