> There are ways to achieve most if not all of these features in Dart

There are. But in my opinion Kotlin-way is more concise and easy to understand.

> it's selfish approach "guy's Kotlin is better than Dart" - it makes newcomers to Dart community to rethink about their choices and move to another community

So non-selfish approach is to say that Dart is a wonderful language, although I don't think it is? Or don't compare languages at all?

I believe that the right way is to say that I don't like X because A, B, and I like Y because C, D. Newcomers can read this article and decide whether A, B, C, D are important to them. If, based on that, they will migrate to Y community, I would be happy for them because they'd made their decision based on some information. Or they don't, but they are aware that there are some languages where it's done in a different way.

> You did not think one main idea

I did. For sure, they've thought about it. For sure, they've had some reasons to make the language look like that. It's their language and they're free to do whatever they want with it. And I'm free to like or dislike the result and to say my opinion on it.

> They tried to keep language simple and attractive.

Maybe that was the reason, maybe not. I don't think that Kotlin is complex and non-attractive, although it has the mentioned features. So it's possible to keep the language simple, attractive, concise and safe (again, my opinion).

> It would be yet another comparison of languages of different purpose.

As I've already wrote in response to other comments, I would say that Dart and Kotlin have more in common than e.g. Dart and PHP. They are both relatively young (the projects started in 2010–2011); they both are claimed to be multi-purposed and suitable for BE, FE, scripts, mobile (and both are most popular in mobile development); they both have interoperability with JS and C; they both can be compiled and interpreted; both companies developing the language have their vision of “cross-platform framework”.

> do You really thing that community must pursue every blogger to get ideas? If You want changes request them in community chat or in issues part of github repo

Well, most of my points have an issue in github already. Some of them are there for more than 2 years. The better I can do there is to vote for them, which I did. Otherwise I will share my opinion wherever seems more convenient and reasonable for me. Of course, community is free to ignore my opinion.