Regarding the plot, I read this too:
Takahashi:"Actually, the main story might be shorter than Xenoblade Chronicles. However, the quest stories are matched up with the open-world game design, so there's more depth to the quests"
And this
Yokota: "That's right. During the first stages of planning, we discussed increasing the number of quests by 3,000%. However, this took place before the development process, so in the end, we ended up creating a similar number of quests as in the previous game. But we did put 3,000% of our hearts into creating them..."
So, even if the main story might be shorter, they put more effort on the side content, and that's what I think XC lacks. Nice to hear that.