I wonder if it's because the only thing people say separates them from the 'pros' in esports is time spent playing. Basically everyone has the opportunity to vie for the grandmasters/whatever rank the pros play at.I know many people who have just the one "hobby" -- and my friends who are similarly obsessed with football, music, skating or reading fantasy novels all seem to be able to branch out to other interests with much more ease than my League of Legends-playing friends.
Really interesting idea. ...I just thought of one of my coworkers. In the workplace 'Secret Santa' we did just now -- on the get-to-know-you list we fill out to direct each other toward gifts -- he listed that his favorite sports team was one from League of Legends. I guess that may be emblematic of this conversation or it may not but either way I got him a fucking scarf.