Yes I'm aware of the history of Angola.

You asked

Are there any countries that use the symbol that are actually nice places to live with good governments?

Angola has made a conscious decision to stick to this symbol as if transitions to a liberal democracy and stable economy. There were some efforts to change the flag recently because as you said it's often associated with totalitarian regimes. But those efforts failed because to Angolans it symbolizes the Angolan triumph over the colonial oppression of Portugal and resistance to apartheid South African invasion.

It could change in the future, Angola is still moving towards "good government" and "nice place to live" as you said. But for now it remains their national flag.