Spears are terrible? Have you ever seen what they can do in the hands of a martial artist or staff user of any kind? They are maddeningly useful in proper hands and the reach on them only serves to emphasize that point.
As for myself... if you're still inquiring on the subject three pages in...
I have somewhat solved the problem for myself. I wanted to have a wide variety of weapons/armors to use, so I had to give them all advantages/disadvantages or even specialties. My "polearms" in particular satisfy a certain niche in combat. I don't actually have a straight up "Spear", as I found that any class I had in the game really wouldn't be using it to begin with. However, I do have a "Halberd". In terms of stats, it's primary function is to be less attack than any sword, while offering some defense instead (which is somewhat rare in a 2 handed weapon in my game). Once you even get past the second Tier of weapons in my game, it even picks up a Speed Bonus that is applied alongside the Attack and Defense. In essence, the weapon becomes pretty amazing in terms of sheer stat gain from a single equip. My Claymores may add 20 Attack, but a Halberd will raise perhaps 10 Attack, 10 Defense, and 15 Speed. It's also one of the few 2 Handed Weapons that actually raises speed (or at least doesn't decrease it) once equipped.
I would also like to point out that there are plenty of famous spear users. Boleraphon (sp?) was one of them. Not really real, but he's famous. What about the 300 Spartans? They were trained primarily in shield and spear play. Weren't they the ones that invented the Phalanx? Let us also not forget that many cavalry throughout history also used spears as a means to unseat or outright kill swordsmen on horseback as it was safer to do so from a distance and meant you didn't have to stop the charge to engage in battle.
In all honesty, swords likely became popular because of their fairly wide usage in Europe, and they became even more popular because when anyone thinks of "fantasy", they all have the image of a valiant knight slaying a dragon with some sort of sword. Don't forget about pikemen and spearmen. They were very important jobs, especially during Medieval Times.
What you need to do is simply make a list of weapons you would like to include in your game and then set about putting them in some sort of niche. It doesn't have to be "realistic", it just has to be a niche. It's what I ended up doing when I had a lot of weapons I wanted included that served the same functions. Katars and Daggers? I ended up increasing Critical Hit Rate on Katars and adding Status Effects to Daggers. Same basic damage, but different effects. Many of my swords do similar things. Functionally, what's different between a Short Sword and a Long Sword? In my game, the difference between the two lies mostly in what stats get boosts. Short Swords are faster and Long Swords are more defensive. You just need to figure out which weapons overlap in your game and start assigning differences to them, even if those differences are arbitrary at first.