Competitive gaming remains a niche market. Tournaments held for games now have prize pools of millions of dollars, but this is nothing compared to the stakes of athletic competitions where professional players make millions yearly regardless of whether their team wins. This is the result of a huge number of factors, but several very important ones are illuminated in King of Kong.
The competitors in King of Kong are not the most charismatic: compare them to an athlete and anyone could tell which is which. This is a small part of the problem: society at large pays athletes so well partially because the athletes are admired. It is much easier to admire an athletic and charismatic athlete than a socially awkward gamer whose athletic skill lay largely in his (her?) fingers.
Another noteworthy obstacle to competitive gaming that exists in King of Kong but is not focused on is variety. There are so many games (even 20+ year old arcade games!) that interest in gaming is far too divided for gamers skilled in only a couple games to make any serious money. There are many high-paying competitive sports: maybe 10 that make a lot of money. In King of Kong a tournament held at Funspot has competitors playing in over thirty games. It would take an impossible number of competitors to fund professional gamers (people who play games for a living) for all these games, and nowadays there are far more games in which to compete.
A final problem is time. This problem will obviously solve itself, but in King of Kong it is obvious that more time was needed for a true competitive environment. Needing to show up in person to compete, for example, is a problem that has now been mainly solved: final rounds are still often done in LAN settings, but at least qualifiers can be done through the internet. Cheating through hacked gameboards is long gone: games are too complex now for that, and cheats are usually incredibly obvious.
Finally there’s the problem of making the games interesting to watch. Donkey Kong is clearly a competitive game, and the intensity with which it was played was interesting to watch in King of Kong, but only a select group of people could sustain interest in watching every second of every playthrough in the movie: it would be grueling. Games need to be appealing even to those not especially familiar to the game itself, just as anyone can watch and be amused by a game of soccer.
I’ve said it before, but I’ll say it again: the day is not far away when professional gamers will garner as much attention and money as athletes. It will just take time and a shift of the industry, with lessons taken from sports and even, perhaps (but unlikely), from King of Kong.