I think Jose was merely expressing his opinion about the primary focus of the show (the relationship between CB) and what would have to happen if the CB situation was resolved. 

Here's what we KNOW:  having the main focus of the show be on the relationship (budding relationship) of CB with the "window dressing" of the cop story and Castle's home life is working extremely well.  Viewership is growing, comments are positive, and everyone is extremely excited about the series and where it's heading.

Here's what we do NOT know:  if the CB relationship were resolved (ie. they got together), then how would shifting the focus to some other aspect of the show fare with the viewers.

I know many of you have beaten the comparison to Moonlighting to death and commented about Scarecrow and Mrs King, for example.  However, what drew you into this series in the first place was the URST.  The witty dialogue coupled with the tension/excitement between CB is fun to watch and is enjoyable to imagine where it might be leading.  BUT, just like most good books, when the "situation is resolved" the book usually ends.  

I think Jose was giving us his opinion that there would have to be a major primary focus shift if "the book" were to continue once the sexual situation/relationship is resolved.