If a fever helps prevent the proliferation of pathogens, isn't it better to not try to get rid of the fever?

Yes and no: You asked a really great question. Yes, fevers do help to kill the pathogens and, as such, are good. However, if the fever gets too high, then it starts to cause bad things in us, including swelling in the brain and damage to other organs. So its ok to leave a fever alone so long as it's not too high.

Fever: Fever is one of the body's responses to infection; so some fever is beneficial (below 102º f). Higher fevers, however, can be detrimental: seizures, brain damage, etc. Children tolerate higher fevers (temporarily) better than adults. If fever goes over 102ºf, treat it (remember, no Aspirin in fevers in children! use tylenol (acetaminophen) or children's advil). If no response after couple hours, see doc.