It is not about Bitcoin. It is desperation. It is simply about stealing what others have. He is not a fan of Bitcoin that is why he did that. He is simply a criminal.
If you want Bitcoin, work for it. Make a place for savings in your regular salary and use it to buy Bitcoin. Accumulate slowly through DCA. Little but little, you can grow your Bitcoin portfolio.
You can reduce your unnecessary spending also like smoke, alcohol, and other vices or costly leisure activities like travels, parties, etc. You can use them to stack Bitcoin instead.
I agree, such a nutcase would also do it if it wasn't regarding a Bitcoin wallet. Such people don't want to work for anything, they just desire what others have and are hateful towards someone else's success. Torturing someone and demanding their money is something only a mentally challenged criminal would do. Okay, if we suppose that he got the money then what? Did he really have the belief that he wouldn't get caught? You need to be extremely naive to think that such a horrid crime would go unpunished.