Retro games are highly lucrative. They don't want any competition to remasters and rereleases, which require a new purchase. Nintendo has been doing this "release the same game every 5-10 years" bs since the Wii (ironically often using ROMs found on the internet).

We're living in a world of frivolous take-down demands, where the law says shoot first, ask questions later, and all the power is concentrated with the copyright mafia. (How meta.)