Does everything have to fit into facts and opinions? I realize many people learned this "fact or opinion" crap in grade school, but if you go by that, either something is cut and dried (we can prove it conclusively), or it's opinion (however anyone feels about it is just dandy). And that leaves out a whole realm of controversial problems where the claims can be true or false, and we have things that can count as evidence one way or another, but we aren't at the point where all reasonable people agree.
Take whether or not there's a God. Do we want to say that's a matter of fact? Well, people have offered "proofs" on both sides, but there's still a debate. Really smart people disagree. Is it opinion? Well, even if there's no proof one way or the other, don't we at least know that either God exists or God does not exist?
Fact vs. opinion is right up there at the top of my list of pet peeves.