Its kind of a weird topic. While I haven't witnessed it myself, what Dulan said could certainly be true, even though on the page where you actually writ a review, it says that bad reviews are ok as long as you back up what you say, like, um...
Good:
This mud sux0rz, I played a week, saw 20 players and 5 imms, NONE of them would help me find the newbie school, they just say to find it yourself. There wasn't a single map either and barely any help files. (add something else here)
Bad:
This mud is terrible, I hate it and you shouldn't even try it.
If the mud admins are able to get reviews removed, they should only be able to demand it on reviews that fit the "bad" criteria.
Now Realedazed, I certainly believe that there is a conspiracy for imms\owner to make a slew of good reviews to get more players, and the only thing I can object to that you mentioned is that "one review said there was a very large playerbase, but the mud was completely empty at times" You might have been on at a bad time, heh...
If you're a regular complainer on a mud and then suddenly there's a bad review, the owner might see it fit to punish your honesty...hmm...Terloch...
So there's fear of punishment, conspiracies, and corruption in the topmudsites side of things. If the person(s) that handled review checking would immediately ditch the "bad" reviews and leave the "good" ones put no matter how much of a tremendous whine the owner puts up.
"And that's all I have to say about that!" -2