If people argue over it, then it's controvercial. It doesn't matter if you think it should be or not. It doesn't matter how valid you think any of the arguments are.
That's one side's argument. You can argue with anything, and then it's 'controversial'. Round Earth vs flat? Controversial! Climate change? Controversial! Basic economics? Human rights? Freedom?
If there are two big sides arguing then that is the definition of controversial. Uncontroversial means there is no big opposition to it.
> You can argue with anything, and then it's 'controversial'.
Yes, that is the definition of the word. I am not sure why you try to define it as something else, something being controversial just means people don't agree about it.
