I think Herb had a big effect because the market was really jittery and all that a stock needed was a little bit of jiggling before it crumbled. Recently, things are so negative that everything is going to hell in a handbasket without requiring any assistance.
In any case, I doubt how much value he added back then. You certainly can't just sell short when he mentions something. Most of the time stocks mentioned even go up after appearing in his column. Somthing he himself has dubbed the Greenberg effect.
Also he is a bit too negative for me. Its a bit tiring when he points excitedly at every single bit of negative news that he digs up from 10k's.
Realmoney just isn't what it used to be (sigh)