Easier to make fun of crypto because at least oil has obvious real-world utility, and (unfortunately) still props up our economy. Crypto is like a sideshow. It's also a hot new topic which makes it fun to argue about.
That's not to defend Big Oil or its shills. That industry should've been hamstrung years ago like the poison market it is. But it might be why HN gets extra riled up about crypto while letting other things slide.