I think that’s a pretty fair interpretation, it’s pretty clear he sucked pretty bad at budgeting. Tiberius was famously miserly with the state treasury, and chances are that young Caligula couldn’t budget and saw how popular he got by just using that money, only to be dismayed at how quickly it went away.

What I find really interesting is the murder of political opponents and how it affects legacy. From where I sit, pretty much every single emperor killed senators, perhaps excluding only Caesar himself, but only a few got saddled with the blood thirsty tyrant image. Claudius killed quite a few senators, some without good justification, yet his reputation is largely “good emperor, misunderstood”, while Tiberius gets off the hook largely because his successor was so much worse. It’s all pretty fascinating to me.