I think the most notable difference is that grand larceny actually deprived someone of something they would have otherwise had, while pirating something you couldn't afford to buy doesn't because there was no circumstance in which they were getting the money and piracy doesn't involve taking anything from them...
Oh I wasn’t saying the two crimes are comparable in their own terms. But specifically the statements made by the comment I responded to apply to larceny as well as to piracy.
Ah yes, the "I wouldn't have paid for it anyway, so I'm entitled to it for free" argument...