The motivation is quite simple. In fact, I can offer several reasons.
By posing as an alternate resource, the operator of that particular blog can create a difference in opinion for writers to puzzle over. Then writers won't know which to believe until after they've been scammed, thus making it easier for the scam to succeed.
For those writers who dislike bashers, the fact that the blog in question only offers positive remarks makes it appeal to them. There are many individuals who want to believe only the best about others. Unfortunately, that makes them easy to manipulate by scams because they still want a top agent even though many claim they don't discriminate because that would be bashing. Even after they become victims, they'll be difficult to convince that they've been scammed because some will be too embarrassed, some too hurt, and some unwilling to become further involved because that would be admitting the "bashers" were right or even worse, becoming what they view as a "basher."
Scammers delight in posing as what they aren't. The more prestige the position carries, the greater their desire to have that position. Furthermore, if they can obtain money while doing it then they don't have to maintain an ordinary job which would involve working for wages and actually producing something. In this case, the scammer probably gets to pose in two positions. One is that of an agent and the other is that of a trusted opinion shaper.
Scammers also want thrills. Posing as something they aren't provides a thrill of getting away with something. Getting money for posing is a means of measuring how much they're getting away with as well as providing an income.
I honestly believe that some scammers also want to hit back at those who are successful within the established system. They view themselves as qualified when they aren't. Posing gives them the prestige and the position to hit back at those who hold the positions of trust that the scammers can't earn.
Then there's pure greed and envy. This comes about when an individual feels the rewards for the position simply aren't enough because the individual believes the effort sunk into attaining that position should provide a greater payoff. This happens to some individuals who've managed to attain high degrees through the system only to discover that attainment of a degree doesn't confer instant recognition nor gratification upon entering the work system nor greater rewards than earned by those without the degree.
