If anything, I think emulators and ROMs help Nintendo and Sony. They definitely don't miss out when someone downloads ROMs. It's not like that person was going to legally purchase any ancient games. And even if they would purchase such an old game, neither Nintendo nor Sony would have made any profit from it.
There's a better chance of someone downloading a ROM, becoming a fan of a company, and subsequently buying future titles from the company rather than the company actually losing money because of ROMs







