To counter your argument, I'd say that's exactly why we would need a "steam discussion" section. We can't stop Steam from being a monopoly in the PC gaming world, but we can still profit from it? Every time I had problems with Steam whether it's a game not running, error codes, game overlayer freezing, etc, where did I first turn to? Google. We could attract new users with an established Steam section with discussion about Steam, PC games, game support, client support, and more. People are going to look for answers when they have a problem, and a majority of people turn to Google to solve that problem. Established Steam section = better site SEO.
Let's not pretend that Steam is this small thing and doesn't need a section. It has over 125 million active users. Yes it's a platform and not a game, but I would think that in itself warrants a Steam section. The Rs Gold buying/selling section is the only section that matches Steam Sales in activity.
I am neither promoting nor condoning the idea of a Steam Discussion section but to write it off that it doesn't deserve a section is ludicrous.