I don't massively object to Sisko moving on from his life as the Emissary but all we've really had since is generic Captain with small child who wants to explore the galaxy which is in many ways the same as Picard at the moment and the sudden need to explore has already been done in DS9 with Vaughn. I don't think it has helped with DS9 recently that not only have we lost some of the original crew but also the first wave of replacements like Vaughn and Shar and very little has been done with the likes of Candlewood or Stinson. Yes Nog and O'Brien are still around but have they actually had a storyline on DS9 of late? Along that point does DS9 have any female officers other than Ro these days? I don't have a wholesale objection to change - though personally I thought it was a mistake to lose Kira from the crew, there was much more to be done with her as Captain - but personally I don't feel that the books have really done anything particularly compelling with the new status quo.