Reduction in numbers of people road racing and inclusion of all groups is a long problem in bike racing and cycling in general. I see people in the Oregon bike racing community doing a lot of the right things - junior development clinics, novice clinics, and women specific clinics for beginners in both road racing and cx are frequent. My club/sponsoring bike shop had a well attended, no drop beginners ride weekly through the summer that taught drafting , pace lines as well as other group ride etiquette and I occasionally see adverts for similar rides from other clubs. I see our local promoters talking to racers and trying to satisfy everyone as far as field combinations at races. Still, road racing numbers are way down over the last few years (I think CX is still quite strong). I think if we looked at it historically, what we need to boost bike racing is an American TdF winner. All I do is thank our promoters and officials whenever I'm at an event, race when I can (which isn't all that often), and help my team promote our team race each year.
As an aside, I also see plenty of social/charity rides in the area, although I don't know anything about participation. Also bike commuting is at an all time high where I live and in many areas of the US. So bike riding is strong, road bike racing is declining.