Mark is, to all known evidence, a true believer. He does not need to be bribed into believing the shit he believes, he truly feels that way. It's one of the reasons he hasn't, to anyone's knowledge, been bribed or subverted into editing for money, he's a zealot by choice.
Ryulong/Micheal Cohen, on the other hand, has been caught red-handed taking money for editing a party line. He has openly admitted he will ignore evidence that proves him dead wrong if he doesn't like the source, while Mark looks the truth dead in the face and calls it lies because, to all known knowledge, he truly believes his own bullshit.
Mark is a pathetic zealous wretch with likely mental issues, while Ryulong is little more than an egotistical jackass with delusions of competence far beyond what he actually has who will do horrible shit in exchange for money and power.