Exactly. Thank you for saying so.
The Chinese army surrounded the block, sent flares up into the sky, and then mowed down the entire crowd with machine guns ... a deliberate massacre.
A few members of the US army, in a tense situation with rocks flying at them, lost it and fired a few shots that shouldn't have been fired. It was over almost immediately when the soldiers realized what they had done. It was terrible, but it was also a mistake, and not an orchestrated, deliberate mass-execution. I don't want to make light of the event; it's just nowhere near the same.
And as you said, every single American student is taught about the Kent State event, and the American military is carefully trained to avoid a repeat. The Chinese government, on the other hand, lets everyone know they'd gladly do it again by working so hard to cover up any knowledge of the event.
So while the one response involves shame and consequences for those involved, the other uses the event to accomplish even more intimidation against free speech.
It's telling that the Tank Man photo is only famous among the 84% of the world outside China. Within, if you ask a young person what it's a picture of and what event it represents, they'll be genuinely confused.
We should also give praise to the heroic measures American journalists of that era used to ensure we had the infamous photo & video footage of the event. They caught it from their hotel rooms, and Chinese officials broke down their doors immediately afterward to confiscate the footage. Let's just say the journalists hid the film really well.