The Tikis are boring. They all are very similar in appearance and they don't do many different things. Now, then we have the Kremlings who shoot cannonballs at you, slide down ropes (so they can smash into you), chase you as you ride on a roller coaster, try to kill you with TWO swords, run around with explosive barrels, fly, and a whole bunch of other cool stuff. They are also much more interesting. The Kremlings are very important to the DK series and are fantastic enemies; they should have been in DKCR.
EDIT: I would also like to mention that Zingers should have never been replaced by Tiki Zings either. They were just awesome. They were always great and challenging obstacles to avoid.