I agree that there are probably many modelers that could learn from looking at models outside of their main interest, and talking to those builders.
Back before the internet, which now sort of sorts us into groups (see the index on this forum), I and all the modelers I knew called ourselves "plastic modelers",,,,we built ships, cars, planes, tanks,,,,,,,visible V-8s and Dinosaurs.
At the shows I go to, we spend almost more time in "other genres" of plastic models,,,,,mostly because I had to go for one main theme to economize somewhat on things here (it worked, too, the stash is down to 600 or so, lol). The Sci Fi and Junior categories catch our eyes the most, it seems.
One show has a definite slant towards model cars,,,,,,,and the resin aftermarket for that group is a lively one,,,,,,,everything from resin engines that you can't get in injected plastic to whole car bodies that were never released by the big plastic companies. A little tip, if you are looking for different colored wires or hoses for a tank or aircraft,,,,,,look at the aftermarket parts in the car section. If you want to learn about high gloss finishes,,,,,,again, bug the car guys. Tiny etched parts and doo dads you look at the locomotive detail parts in the model railroad section. (diorama stuff too)
Rex (3 weeks until our next show, who knows what we will see at that one?)