If you look at the contrast in our two examples (mine being tonally facetious, of course), you'll note a crucial difference: yours are set in easily understandable contexts that don't require the reader to know or understand anything about the world they're in. We all know that Jupiter has moons, even if we can't name them, so we know what having one of them disappear will mean to everyone – we can imagine a public panic, newscast footage, conspiracy theorists, military generals talking invasion...etc. We all know what it means to find dad dead at a lake with a bullet.
But not all settings or contexts are implicitly understood (hence my use of lots of bizarre in-world terminology.) The novel might not be about people dealing with regular people interpretations of things. It might involve an unfamiliar world with unfamiliar customs and unfamiliar relationships. That's why the sci-fi and fantasy genres have often sought to use prologues as a means to create a bridge between the reader and the world of the story.
A large proportion of the crime novels and thrillers I've read recently use prologues to set up the character. Sometimes it's great, sometimes it's not. However the ones that try to start inside the action with an initial driver are equally uneven – sometimes it works, sometimes it feels incredibly rushed and you get this important event without any character context with which to interpret how it affects them. So then you end up having to find out after that the person who discovered dad's body either loved dad or hated dad, and the immediate emotional impact of that scene is lost.
It's funny you say that because I find I spend a huge amount of my time as a novelist trying to find exceptions – looking for a different way to set a scene or give twist things around. My fourth novel, Tyrant's Throne, has a 17K opening that has almost no direct connection to the events of the rest of the book except that it parallels the entire story in miniature – something the reader (and characters) only realize at the very end of the book. That doesn't mean its genius or that everyone will love it, but the series has been successful so I keep trusting the instinct to look for different ways to approach the stories.
To put it more simply: there's nothing inherently wrong with beginning with your initial driver, nor is there anything inherently wrong with a prologue. They're two of a range of tools available to novelists and generally speaking, it's best to keep that toolbox as full as possible.