I am a professional bird and wildlife photographer that takes 1000+ photographers out in the field on tours each year and I have been doing it for over 20 years. I am not sure where your "...but those are the minority." data came from, but from what I have seen over the years there are a lot of people in the world with a lot of money and they switch systems and shoot multiple systems. Since Sony came out with the a9, then the a9II, and now the a1 I have seem many of my repeat clients switch from Nikon and Canon to Sony. Many of these folks shot the other systems for many years and where highly invested in those system. This is just one example. These people are not just professionals, but also enthusiasts. There is inertia as you put it, but also thousands of people who go with the flow and switch systems to meet their desires. Within the realm of bird and wildlife photographers, I am not sure those who switch systems or shoot multiple system are a minority, but instead may be closer to the majority, and there are a lot of wildlife photographers out here with more joining their ranks every day. Just one persons somewhat educated perspective.