The problem, as I see it, is not maturity.
It’s perception and product design.
Being an early-stage software doesn’t necessarily mean being unfriendly.
When XboxMediaCenter (XBMC, today Kodi) was released, the first versions were buggy and feature-limited, but were usable by the avg layman. Their focus was on creating a super-friendly interface (that did required some tweaking and manual configuration, for some cases) and they delivered. This is what made it popular. Instead of navigating with Windows Explorer, you could navigate with a nice graphical menu on your TV.
I think HA should be made the same. Some simply, generic, core functionality (like “turn the light on at sunset”) can and should be done in a super friendly way.
Putting a UI together won’t solve the problem, I think. You can spend hours trying to teach my father the difference between am automation trigger and a condition - I doubt he’ll understand.
I believe the product layout, the whole paradigm, should be different. Not creating UX to help the average Joe build configuration files, but simply creating building blocks that a user can simply configure. For those who required unique setups - they can ask for more flexible components or even resort to writing code or YAML.
If things were built that way - I would have been in a whole different situation now.
AD is not a real solution. It’s great for me (actually, I’ve already converted most of my YAML to Python code and it’s wonderfully easy for me) - but I don’t believe HA defined its target market as developers or even tech savvy users. It would probably want to cater to the needs of average users, those who don’t want to invest lots of money in high-end sophisticated (and easy to use!) home automation systems.
I’m actually playing with that idea - of building easy to use building blocks that include everything you need, including the UI. It can be based on this wonderful HA engine but will have a completely different approach. It is a huge project, too big for me probably, but I truly believe this can be a cornerstone in making HA a mass-production league of a product.