I think the reason is because LightWave users these days are mostly hobby users who like to play with FX tools in LightWave. Clouds, water and smoke get the most posts/views/replies on the forums.
Then the studios using LightWave are also primarily using it for VFX shots. It should be no surprise as that is mostly what LightWave was used for when it was most popular over 15 years ago.
LightWave is all but dead now. However I think they have kind of figured out a way to financially keep it plugged into a life support machine with a few developers squashing bugs and maybe over time gradually adding some features. They don’t appear to be putting any effort into the promises made over the last 3 years which it too bad, considering those promises and the groundwork for the future was left incomplete. There is no roadmap or any clue as to what is to come. But it is pretty obvious with the few people left, that it won’t be much.