This is a useful term. It helps us understand a topic or theory that can be considered from multiple points of view by people engaging with good intent.
“Pluto is a planet” was a controversial statement among some people who study the solar system.
On the other hand, it’s not controversial that Pluto actually exists.
Choosing to engage in a conversation about something that’s controversial gives us a chance to share our insights and engage in dialogue. And it also comes with the knowledge that we’ll need to devote time and care to having that conversation.
On the other hand, inventing false controversy is simply a tool to keep people away.
If you insist that the world is flat, and that talking about its spherical nature is controversial, then you’ve made it hard to be a travel agent, a geologist or a sailor. You’ve scared people away from a productive conversation because you’re claiming something without good intent.
The key element of ‘controversial’ is possibility. If that’s not there, it’s simply an empty argument.