lol i agree with yu haki73, he sent them away as a favor to dragon,sparing luffy and his crew....wow, yu guys really cant guess why robin met with the revolutionaries?? "question the world"-dragon says to luffy at loguetown.....prof. clover mentions that the "ideals" of that "ancient kingdom" wuld be more of a threat to them than any weapon....robin is interested in history....the world gov is after her....luffy said he and his crew wuld stand by her no matter wat... dragon is thus far a bit shady, his plans/goals arent that clear.....HELLO!! this culd be oda's way of intricating dragon into the plot!! plus if yu've noticed, evrything in the series seems to be related...almost as if oda is going for something BIG! proof off that is in the whitebeard war and how much it was hinted at before it got started!....in short, oda is laying the ground work for the next big thing, and if my man's intuition is correct, the "last" enemy the straw hats face, will be the world gov.....thanks for listening punks!
this was my prediction/comment along-long time ago..nd i still think it culd be a possibility.. wat do yu guys think?