Seems to me the success of these groups/people is more just a function of having access to the amount of funds one needs in order to make this a profitable endeavor. Except for the primary discoverer of the game's quirk, it is just people with money/funds taking advantage. Much like any almost sure thing investment that requires a large amount of capital. Only those with the means can benefit.
Similar to say investing in stocks, bonds, real estate (assuming a rising market and modicum of investment sense.) Joe Anybody might know of a "sure" thing, but unless he has the money or can convince someone to invest the money to his benefit, he won't be able to take advantage.