Simply go to each category of RC listed on leading forums, and look at the count for logged in members/guests, number of posts, and you see what is alive and what is dead. Feed the more active categories and cater to them, and you have a handle on how a lot of things succeed, understanding the demographic and what they want.

Resisting change is a flaw of human nature, and there is no room for that if you want to make it. RCU resisted change but I see those new threads in the infant stage of contributions. Unfortunately I'm a glow guy and haven't given up yet on my kits and ARF's to be any help in that new category or I would.
Maybe I should change?

It's like a car forum catering to owners of a 1998 Crown Victoria instead of a 2017 Honda Accord. They sold a lot of Crown Vic's I'm sure, but who cares about that today, even if it rides nicer?

Imagine the short time 'multirotor" was even a category, nothing comes close to it on RCG. Vendors and forums might want to reset some priorities if they're going to make it.