For me, this was one of the greatest games I've ever played on the PS1 when I was a kid. The story was amazing, the art style and aesthetic was phenomenal, the combat, while a classic turn based, was very fun and actually made me have to think on what to do (aside from how easy battles got after power leveling). But what always got my attention the most was the sheer variety of Dragons that Ryu can turn into. I didn't play this with anyone else because at the time, no one around me was as interested in RPGs, let alone games in general.
As for why I want to have this on GOG, I saw over the last few years how many people love this game like I did. I think that having this game preserved on GOG would make a LOT of fans like me happy. To have this game digitally but able to play in any way we want that we were not able to on the PS1? It certainly makes things more fun.
I have this game's digital PSP version on my PS Vita, but I also would like this game more easily accessible to a LOT more people who have heard of this game and seen videos of it, but never played it.
This way, at least the game would be more easily preserved not just for game preservation, but also a piece of RPG History.