There are many ways to define a pro.

Snarlygribbly says that you are only a pro if you make your living at it.

SAMS3D talk about talent, skill.

And then we have style and taste.

Myself I go after ambition.

And there are probably a dozen more.

But one thing is sure. There is a huge difference in how much time, money and recourses people lay down on their projects. There you have some tangible that can be measured, that is not subjective.

Quote - "I don't really understand why labels are important."

It is important because if you don't know where the other peson stand you have problems understanding each other. That is the main cause of misunderstandings in this forum.