Could one be forgiven for assuming on the internet that people know what "console gaming" or "the 1990s" are? I expected the worst reading this comment thread before clicking TFA but it's really very straightforward.

It really depends on the context.

Everyone's bandwidth would be saturated if no one assumed their reader knew what they were talking about, but assumption is a form of lossy compression that allows both miscommunication and misunderstanding.

conversely: never assume the writing is for everybody :)