Give me the Death Note, I can be trusted to act rationally. The only “undeserving” to end up on it would be people who step through Metro doors and immediately stop, even though there’s people behind them.
More seriously I know the author has said it’s about power corrupting, but if that’s the story he wanted to tell then he should’ve chosen a different protagonist. Its also a silly mantra, we do not live in a Tolkien novel, power isn’t some supernatural force.
It’s been years since I read the manga or watched the anime, but IIRC you’re right, and Ryuk tells Light early on that most people who’d get the death note would immediately want nothing to do with it after realizing it’s real, rather than a prank.