FF14's failure was not because they wanted to step away from FF11. That in itself is a decent goal to have.
FF14's failure was due to horribly inefficient development teams, a lack of decent management, an arrogance and complacency that their fanbase will eat up whatever schlock they can serve to them, and a misguided belief that they could release an incomplete game early and just fix it later with patches, as they admitted in this interview:
http://www.gamespot.com/pc/rpg/final...and-sage-sundi
fake edit: what Ashthra said