I'm using Chef since 2010 for myself and customers. I never understood the hate but I saw so many developers not getting it and/or overengineering it to a state which was beyond their capability to debug.

For example the different levels of attribute types. I saw "senior" developers writing nasty Ruby code (actually `system("rm -rf directory")` to delete directories (outside the chef DSL) because they didn't understand the appropriate chef resource.

The market decided to take away the power of a real programming language DSL as an interface. People are now forced to deal with terraform (HCL), YAML or JSON. It's a lobotomy.