Agree - one of the things we've found using Starlark at Kurtosis is even the small jump from Python to Starlark makes people think, "What's this Starlark? I don't want to learn a new language", and we have to show them how not-a-new-language it is. I can't imagine bringing a truly new language like Pkl to folks and having them enjoy it.
I thought the same thing with the Godot game engine's GDScript. Aside from a few class-level implementation details (IIRC, it's been a while) it's essentially Python, syntactically. "Ugh... If I'm going to learn a new scripting language it's not going to be application-specific... Oh NM."