So you expect people to be different just because the topic is philosophy? — Marchesk

I expect people to do philosophy, and be philosophical, on a philosophy forum. Whether that's the same or different from the rest of the web is of no relevance.

Doing philosophy is exactly an exchange of of information and viewpoints.
— bert1

Is it? — Marchesk

No, it's only partly that, you're right. It's also critical evaluation of those views, identifying inconsistencies, fallacies, suggesting repairs to arguments, making implicit assumptions explicit, and so on.

Is that what professional philosophers do? — Marchesk

At their best, yes, (assuming my revised statement above).

Or do they also advance their own positions? — Marchesk

They do that too. In the process of doing that they critically evaluate their own view as well as others, if only to be seen to be playing the game.