Having a "cabin guru" website would be virtually impossible to gather all the information needed. There are a dozen (at least) different cabin classes on each ship versus two or three seat classes on an airplane. Within each cabin class there are numerous different variables such as stern or aft, floor, view, and proximity to any elevators, gathering places, service areas, mechanical components, etc.

And gathering this information would be very difficult. Each cruise line has very different ship configurations. Ships are not like airplanes where you can buy a ticket and walk through it is a few minutes and visually see all the other seats. And they only sail every week or two so there is not the same amount of data available as planes where there are up to dozens of flights every day for similarly configured planes. It just would be impossible to gather this information.