Though, maybe in practice Calvinism deviates from theory.
Obviously not everyone believes all of it to the same extent, and they may have a softer padding between these beliefs and how they act within the real world, but based on my experience (30+ years of living in small Calvinist communities) most people who take the title Calvinist, and even most who rather take the label Reformed (because Calvinism has earned its bad name) do believe this to a fair extent.
Disappointing to see your unusually extensive first-hand experience downvoted to the bottom of this sub-thread.
Philosopher Slavoj Zižek argues that it is religion/ideology that allows for the commission of atrocities, by ascribing cosmic importance to otherwise banal conflicts over resources and prior injuries.
In nature, predatory animals might hunt prey to extinction and then die off themselves. But this is more likely to happen in theoretical models or very isolated/extreme environments with an unusually narrow 'fault tolerance. In more complex environments, adversarial populations wax and wane chaotically, selection pressure yield evolutionary innovations and arms races that allow breakouts from local minima, and so on.
A History of Warfare by John Keegan is a good introduction (with an excellent bibliography) to the anthropology of warfare, and has a particularly good treatment of initially adaptive social mores can end in catastrophe when they bump into resource limits or experience an external shock. Keegan emphasizes the role of technologies (both physical and social) which confer overwhelming advantages in conflict, which may or may not be sustainable. For example, pastoral herding/hunting practices developed on the large scale of the Mongolian steppe allowed nomadic hordes under leaders like Genghis Khan to overwhelm less dynamic agricultural societies. But lacking deep administrative foundations (quite literally, due to a lack of construction materials and incentives) they were unable to lock in their massive tactical advantages over a longer timescale.
War by Azar Gat has a deeper exploration of competition between socio-cultural systems and incorporates fresher scholarship, but at the price of being somewhat more tendentious and a much less engaging read.
If you're born to a wealthy privileged life, this belief says that you deserve it because you're one of God's chosen- that's why life is so good. And it's a good thing that all those bad things happen to other people because they are bad people. God didn't choose them.
This is an extreme view, but the seeds of it are everywhere in our society. Just the term "bad guys" is used to imply a generic evil that we need to stop. Meanwhile real life is far more nuanced (with most true sociopaths actually doing very well in finance and politics).
Predestination is a much more mainstream Christian doctrine that has nothing to do with "good people" vs "bad people", or even "good actions" vs "sinful actions". Predestination means some people are "destined" to salvation and others are not.
Predestination is a challenging theology that has to balance God being all knowing (omniscient) and free will.
Presumably, the Calvinists believed that Peter, Paul, and others were predestined to be saved, and that Jesus was on the right side of history.
This is the first I've heard that John Calvin preached that bad things don't happen to people who are predestined for salvation.