It really does come down to “We wanna maintain copyright in case some day we randomly decide we care enough to try to make money off of it.”
Back when Chrono Trigger DS came out, people had been making fan sequels for a while. Squeenix suddenly started sending cease and desist letters, while someone at the company (I think a vice president, but it’s been a while) basically said they’d never make a sequel because people needed to buy this $40 half-assed DS port of a game they already had on other consoles to “prove” they want a sequel.
At the time, Squeenix had a support E-mail account. I sent an E-mail to complain, and their response was all about how the company needed to protect copyright in case they decided to make a sequel some day.
It’s 10 years later, they still haven’t made any kind of sequel to Chrono Trigger, but they’ve also still decided fans aren’t allowed to make any kind of sequel to satisfy a demand that Squeenix won’t fill. Companies would rather let IPs and characters die in obscurity than enter the public domain.



