Similar experience here. I've proposed a few changes to the language and none have been accepted. Rejecting convenience features with no downside like concise object literals is unfortunate. It literally took over four years to finally get arrow functions into Haxe, which had overwhelming community support.

Change proposals are subjective, so people can have different opinions on whether a change should be accepted or whether it was well-formulated enough. What bugs me though is that the Haxe team has a documented process for considering and voting on these proposals, which they don't follow. If Nicolas doesn't like a feature, it's essentially vetoed. If he changes his mind later, it'll be implemented without any further discussion. Most discussion happens in an internal Slack channel so there's no transparency. It's essentially a BDFL masquerading as a democracy, and it can be frustrating to try to contribute as an outsider if you don't realize that. See inline XML for example (https://github.com/HaxeFoundation/haxe-evolution/pull/26) - a lot of discussion, open questions remaining, seemed like Nicolas was generally resistant. Then suddenly, there's a PR and it's merged, and it will be in the next version of Haxe.

IMO, this is not the way to run an open source project. And in my experience, the team is resistant to feedback and takes things personally, so I've lost confidence that it will change.