Uhm, no - XIII/XIII-2 were successful. Just because you have an extremely vocal group of people (especially western people) stating they hated it doesn't make it a flop, the series
idea may have flopped, but the games? Not so much. A "flopped" game doesn't score high with Famitsu since even XIII-3 scored lower than XIII-2 (perfect score) and that's still a 37/40.
Not to mention Type 0 (originally XIII Agito) was probably one of the best FF games, especially modern times, yeah..XIII is far from a flop, but I'm pretty sure people will say "score means nothing", which is cool, people use score to justify other game's success every time
