As a Jew, I feel so safe for my future know that genocide as a term has been diminished to "When the government kills people".

Say, on a completely unrelated note, did you know that 23% of American adults 18-39 think the Shoah was fabricated or exaggerated?

Also, I guess genocide also includes people resisting genocide, apparently.

Okay, you said "tankies are defined by their defense of genocide" but then say that there was a massacre in Tiananmen Square.

For one, that's false. No massacre has ever taken place in Tiananmen Square, and if you could find me a source that says otherwise I'd welcome it.

But also, massacre is not the same as genocide. There must be something else you're talking about.