The bar is very high for shipmodel builders, because even though they are building plastic kits, the build quaility can (and often will) be compared to something the model viewer has seen in a museum. The detail standards, etc., are set very high and can demand a time and effort beyond many modeler's pain thresholds.
The only work log I've kept on a build was for the Revell big Constitution I constructed 30+ years ago. It took 500+ hours over almost two years to finish it. At the time I was hanging around with a bunch of shipmodel builders which included Dr. Tilley, so my motivation was high. Everybody's models took a long time, so by their standards no one was in a rush.
I believe the one thing that makes ships somewhat different than other model subjects and the details required is that a ship model represents a unique one of a kind thing. Yes, there are ships of the same class that look superficially the same, but as a shipmodeler can tell you, no two ships are identical.
I can build a F6F Hellcat fighter, make sure I have the canopy and a couple of other points correct for a -3 or -5 variant, apply some decals and representative weathering and I'm done.
To do a shipmodel justice, that type of build may not be considered enough. A WW II aircraft carrier went through rapid changes during the war. What paint scheme did it have at what time, what was the antenna suite like during the spring or fall of 1944? Did the air group have SBDs or SBC-5s?
While that amount of research could be applied to a Hellcat fighter model project, few modelers would expect it. Did Campbell's F6F-5 fighter have heavy exhaust stains during the "Turkey Shoot?" It could make a challenging project, because details like that may be hard to track down.
Many ship modelers would believe that level of research is expected of them for a project. It is the nature of the beast.
Is it necessary? No. Everyone should build their projects they way they want to. No modeler should be surprised though, if building a shipmodel, that tradition requires a higher order of work than other projects. It comes with the deal.