^^^ The reason why SE is not as successful as before, is directly linked to the loss of talent, the decline in quality can be traced back to sakaguchi's departure, not only was he the creator of Final Fantasy, but he had the talent and sense of knowing who of his personel worked well with each other, for example you yourself mentioned ito and kitase, those two are my personal favorites who still work for the company, and when they work together, they create Classics! Sakaguchi know how good ito was, that's why he paired him with Yazmat to created FFT another classic, kitase is a good writer, but gets absorbed into the scenarios and makes the games feel like a movie or a book, with ito on his side, they make interactive books or movies, look at FFVI for example. Look at the creator of Xenogears, left square because they screwed his gem of a game, created Xenosaga and Xenoblade (The best JRPG ) title in the last 5 years, and you can make the argument for best Jrpg of the decade. Sakaguchis The Last Story, is a very well made game too, certainly feels more like a FF than FFXIII.
Dark souls is not a 360 exclusive so i don't know why you mention it, when we are talking about 360 only titles :/