Hartzell was in an impossible spot. Without Abbott a difficult spot.
The difficult spot - I think his letter was in hindsight hot garbage, but with large crowds, national frenzy, the hot button issue of Israel / Gaza, the current landscape of mass shootings and more the campus was not exactly safe even if the demonstrators were 100% within their rights which I believe they were until overwhelming evidence suggests they were not.
The impossible spot - I think Abbott is a piece of pig shit, I think he’s a thug and a duplicitous power addicted MAGA slurping cumstain. And Abbott was keenly interested in a political stunt. Assuming Hartzell is not an Abbott yes man by choice, I really don’t see how he could stand up to Abbott without risking a whole lot more.
Who is at fault - well besides the obvious blame on Abbott himself, we the people are to blame. We have what we elected, we deserve what we get.
if everyone of those protestors voted in elections, donated time and money (even if very little) to elections, we would be well on our way to being a better Texas. Basically, protesting is a distraction unless you donate, volunteer and vote.