Only one person opened fire. He got 100 years. (I agree that he shouldn't have gotten a slap on the wrist for what he did, but I'll happily point out that killers serve less, if at all.)
The rest got 70. None of them had guns.
The guy who got 30 years wasn't even at the protest.
---
There is no universe where this is not completely batshit insane, but it's interesting to see you use the exact same logic[1] the CCP has in its crackdowns and pogroms to justify it.
The reason the sentences were so high, by the way, was because the judge took dozens of minor offenses and added the sentences for each. It's the equivalent of sentencing someone who stole a 12-pack for 12 counts of theft, or someone tagging 'FUCK ICE' for 8 counts[1] of destruction of federal property.
For some reason, the current regime does not hold its footsoldiers and other useful idiots to the same standard.
---
[1] Someone in a protest/movement/group did something bad, brand them all terrorists, and make sure that everyone's going to a 're-education' camp for what will remain of their lives.
[2] One for each letter, and another one for the space.
I think your confusion comes from the fact this wasn't a protest gone awry, it was an organized domestic terrorist attack. It was a small group of armed people in body armor who privately organized a domestic terrorist attack intending to cause damage and hurt/kill federal officers in an ambush. The only reason the officer lived was because Song's gun jammed before he could kill people and get away.
Certainly if this was a jihadist attack, a lifetime sentence would be appropriate. Why should it be different just because they're white?