Unfortunately, that sort of mindset is depressingly common. People get these machines without realizing they have to be maintained, and when the time actually comes that they've gotten busted up enough that it's clear something is wrong even for non-fans, they have no clue how to repair them or are too frustrated to go any further. I don't think there's that much of the "cutting out the middle man," as that would imply they know about it in the first place. Rather, I think most of these owners who never ever maintain their machines obtained them without being aware of their maintenance needs until it's too late.
Most often, what I see happen next is that they sell off the machines (at a loss if needed) and leave pinball forever. It's a real shame, and there really isn't a way to get through to these operators except one by one as they're not part of any pinball-related groups.
Regarding that, I'd like to make a suggestion: Notifications can work if the user picks specific locations, such as their favorite places or the places closest to where they live.