Moving from technique, form and equipment to art???

[Q.G.]

I think you are right: the understanding of what art is, but much more even the way it functioned in society has changed a lot since then.

But even then noone would have told someone that he could not be an artist (whatever that meant then) because of themedium he or she used.

Think of it as of a pen: people use it to write shopping lists. People also use it to write literature.
It's not the medium. It's how, and to what end, you make use of it.

Photography is a form of art. Not all of photography is. But definitely some of it.

[benjiboy]

Good QG I'm glad we agree at last

[Casey Kidwell]

Just to play devils advocate, the tools follow the art, not vice-versa. Some of the most competent and knowledgeable photographers I know are also some of the most shallow creatively. At the same time I've known some artists who are painfully (to me) ignorant of technical photographic knowledge but have brilliant "eyes" and minds and work with a conceptual complexity that wasn't learned but just possessed. And I hate them. Also, art doesn't care what society thinks.

[Q.G.]

Also, art doesn't care what society thinks.

You are thinking about art as a pursuit of beautiful thingies?

Art, back then and certainly now, does care what society thinks.
It's part of the thinking society.