Probably more work to port to a non-PS console. I assume some coding may be shared between PS2, PS3, and PS4 that just doesn't exist on Xbox/Wii/PC and would have to be rewritten. I could be completely wrong though.
Nobody HAS to do anything. You are not forced to buy this if you already have the Vita or PS3 version. As with a lot of other games like GTAV & TLOU, it's good to have this on a current-gen console(s) since a lot of people already started to save up for & move on to then-next gen from PS3 a long time ago.
Still had the tab open in Chrome when I first saw the thread.
I'm pretty happy at this news. PS3 was 720p30 with 2xAA or 1080p with no AA. I would really like this to be 1080p60 with some decent AA, surely 1080p60 with 4xAA isn't unreasonable. I didn't get the PS3 Collection but I'm glad I waited.
But why would it be a bad thing to port the FFXIII trilogy to the PS4? I'm pretty sure there's a decent amount of people interested (me included), and it probably wouldn't take a lot of resources/time. My PC sucks, but I'd love to play LR and XIII-2 with a decent framerate.
If they are going to remake it it even half as greatly as FFX, then it's not going to make itself in a few months. They need to set up a team (or make arrangements to outsource it) and it'll take a while given how massive a game it is. If they are currently remaking it and still not just thinking about doing it, it'll probably be a end of summer 2015-early 2016 release at earliest.