[orangecat]

Why is it so horrible as a systems language above C?

It's not "horrible", it just has many slight-to-moderate deficiencies and annoyances that make development more work than it should be.

Is there any other language that fits this role in a better way?

Scala is strictly superior when used as a "better Java". (If you go deep into its functional capabilities you get a different set of tradeoffs). C# is better as a language, but then you're tied to .NET.

Really we'd need to know more details of what you're doing and why you believe Python may not work. Are you concerned about performance, or do you need to do things that Python doesn't have convenient APIs for?