Think about tools. An opinionated tool is one, where the designer/maker thought about every corner, nook and cranny of the object and decidedly took the decisions that served the higher goal they envisioned for this tool. "Opinionated" does not automatically mean radical, it means that you have that higher goal about what makes a good tool and you are willing to go to certain lengths in reaching it. Sacrificing everything for that higher goal would again be radical, sacrificing nothing for that higher goal (or not having one to start with) is unopinionated. A text editior like vim for example is opinionated – it does not want to be everything to everyone, but it wants to do the things it was intended to do well. Even something simple like Notepad.exe might be opinionated. Just a bare bones simple texteditor, not intended to do anything fancy.

Something like Microsoft Word would be less opinionated, it tries to be a lot of things and is only good in very few of them.

A good screwdriver is opinionated, a weird multitool that is bad at most things while also being clunky is not. A swiss pocket knife is opinionated again. Punk music is opinionated, so is jazz or drum and bass. A certain type of pop music that tries to please everybody is not. And that punk band doesn't automatically get unopinionated, because they add a little dub flavour into their music as long as they still know what they want and why.

In my eyes being opinionated is a good starting point, you then just have to decide whether the thing you decided for is the right opinion for what you are willing to achieve.