In an interview with Game Developer, Motomu Toriyama and Akihiko Maeda says that they tried to make Final Fantasy XIII more attractive to Western players but weren't able to go all the way. "The sentiment that stood out the most to us at the time was the increasingly harsh criticism towards JRPGs," they say about how things looked before development of the title started in full.
A lot of tests were made in the West and Square Enix did get a lot of feedback - linear stories and commando based battles were things that players didn't want.
"Unfortunately, we were already quite far along in development, and knew it would be too late to implement most of the feedback from the player test sessions."