I would say they base the list on who can exert the most force on the industry, same as saying the most powerful people in the computer software industry or something like that. And I don't see a name on the list that I really disagree with, all those people have considerable weight in the industry and when they talk, people tend to listen. When they make changes, people tend to follow. Note however, that equipment companies are not highly represented on the list, the highest ranked equipment exec is #17.
Also, something to consider, a fair amount of this is based on how much these people spend to 'grease the wheels' so to speak. Same with 'Best Course/Top 100' rankings as far as I'm concerned.