He's an US senator, he's probably angry steam didn't yet banned all Russians, Chinese and muslims.

Considering some of the community threads I've seen, they might actually have a point

They provide a bunch of other services tied in, like the reviews, Workshop, and most infamous, guides and forums. While the reviews and Workshop tend to not be too bad (although still often not great) the forums and guides tend to be completely unmoderated and as a result, devolve into spam and extremism.

Steam is a game purchase platform and game running environment

You just left out part that it has extensive community features too.

Community Forums