I don't think that's right. I've never seen anyone claim that it was no big deal and doesn't reflect negatively on the politics of the 1970s.

There were people who argued that the shooting was the students' fault, certainly. But the students knew at the time that they were antagonizing people, and felt that it was worth the risk, predicting (correctly: https://emersoncollegepolling.com/50-years-after-kent-state-...) that future generations would see why their cause was worth fighting for. The only lesson I can see to take away from that is that violence is not the last word, and you should (as students at the time did) keep protesting even if people get shot for it.

I suppose there's also the lesson that de-escalation is an important tactical skill. But that's not controversial at all. Many recent National Guard deployments have been extremely conflicted (I'm still mad about them!), but both guard members and protestors have done a solid job at not needlessly antagonizing each other.