People were using the official plugs as templates and releasing their version.
Other people were downloading those plugs and expecting official support when they broke.
Another thing that became an issue is the use of undocumented non sdk features.
It still is, don't do that.
So yes designing your own plugs is a bit convoluted, especially since behaviors that work with other behaviors... cough solid, are basically black boxes.
Historically, plugs have always been an issue because of the things mentioned, and because third parties don't tend to offer maintenance for a long time.
Its a hidden problem of codeless development.
That being said, there is a code option, for the sdk, and a scripting api for the editor. That might be a better solution for you.
I say this, but you've been a member since 2013, so some of it should be old news.