It's slowly moving out of the hobbyist realm though - there has been a consistent output of "stable" releases with very little problems upgrading.
One reason it hasn't gotten much traction yet might be because the perceived benefit is too low to convert existing systems: You can upgrade in place, downgrade, manage a whole fleet easily etc, but the people with these problems already have (bad) solutions for those in place.
So there's a lot of inertia, and uptake has to come from new installations.
I too managed a Chef based infrastructure, and it was terrible. I don't like it when simple deploys break a production system because of a missing comma in some config file. With NixOS/NixOps, many issues that Chef has just don't exist.
One reason it hasn't gotten much traction yet might be because the perceived benefit is too low to convert existing systems: You can upgrade in place, downgrade, manage a whole fleet easily etc, but the people with these problems already have (bad) solutions for those in place.
So there's a lot of inertia, and uptake has to come from new installations.
I too managed a Chef based infrastructure, and it was terrible. I don't like it when simple deploys break a production system because of a missing comma in some config file. With NixOS/NixOps, many issues that Chef has just don't exist.