Contrary to what most people posted here, there's nothing wrong with thinking the game lacks replay value due to a poor design decision (among other reasons). Some people can enjoy gameplay more than story, and there's nothing wrong with that, but to say one is objectively better, carries more weight, or automatically supercedes the other at all times is just plain, personal opinion.
The second half of the game can be done relatively quickly, it's not a whole half of the game really. Is it a poor design choice? Well, many people seem to think that it is, including myself.
Does BD lack replay value? Arguably, depending on how much grinding and messing with jobs you do, and if you played on Hard, and filled out the bestiary the first time through. It essentially comes down to playing for different setups, a handful of skits, and Nemesis'. Some people enjoy that, some don't.
"Showing off is the fool's idea of glory" ~ Bruce Lee