I think some of this might be related to the nature of the beast - books. Because there are only a handful of written adventures as opposed to weekly episodes, you want every instalment of the Titan's adventures to be challenging and meaningful, and one way of doing that is placing the crew in such positions of peril that they take casualties (i.e., 'if people die, it's important). But also because there are so few instalments, you basically get a situation where Riker and the Titan suffer casualties or otherwise come close to destruction every time we see them. What's worth noting is that the Titan probably has a whole slew of sucessful missions that go off without a hitch in between the novels; the books represent 'major' incidents in the vessel's journeys.
Fictitiously yours, Trent Roman
Fictitiously yours, Trent Roman