Disclaimer* I haven't read every post in this thread yet so I apologize for any redundancies. Also, I'm not well traveled so can only talk about my local experiences. I also would like to mention that 75% of my dealings in the hobby have been online. Therefore I have no clue as to their race.
I have only bought a handful of machines. Most of them from the same person who is a white Male. But since I have limited experience in meeting and dealing with people that may qualify as enthusiasts, I will comment on my local public pinball playing experiences.
I live in St. Louis which is a diverse city that has different areas (we have an Italian neighborhood that is predominantly Italian, a neighborhood that is largely Bosnian immigrants etc.) There are 4 or 5 "pinball bars" that I am aware of in STL that are all located in different ends of town. I feel like this is because pinball has diverse appeal. When I go to one of these bars, you see the type of people that live in that area. There is one that I am sure has predominantly white customers but there is another in the historically LGBTQ neighborhood that is very diverse and another where sometimes I'm the only person in there without a face and/or neck tattoo.
Ultimately, people like pinball. But I am sure the price point is high enough to where the ownership demographic skews white male. I mean just look at some of the theme selections.
I guess it depends on what qualifies as an enthusiast.