Partly because I can, because unless you go absolutely wild with excess it’s the RAM equivalent of fuck-you money. (Note it’s unified though, so in some situations a desktop with 48GB main RAM and 16GB VRAM can be comparable, and from what I know about today’s desktops that could be a good machine but not a lavish one.) Partly because I need to do exploratory statistics to say ten- or twenty-gigabyte I/O traces, and being able to chuck the whole thing into Pandas and not agonize over cleaning up every temporary is just comfy.