Why didn't M$ make abiiger play for final Fantasy?

[Dgc1808]

I seem to remember to FF leaving nintendo for ps1. Mainly because the ps1 had a bigger storage media for games [cd over cartridge]. Why put FF13 on DVD9 and limit it when they can have a 50GB bluray at their disposal. And imagine if it ends up a 2 disc bluray game [2 50GB bluray disc in the box]