Some basic facts:
1. All the things you can do with a spear, you can do with a polearm, and the other way around. Polearms just have more weight and a larger cutting edge behind them (
most spears have a cutting edge too, though!).
2. Consequently, with polearms it makes more sense to swing them - with spears, it's
very situational, and not done usually unless to keep someone at a distance.
3. On the other hand, spear are
fast, Very, very fast. Combine it with their reach, and you have quite a deadly combination, though it requires a skilled fighter with place to maneuvre to exploit fully.
4. Consequently, a spear fight is
more dynamic, with more moving around and trying to get an edge, than a polearm fight - not the other way around.
5. Spears make better tools as well. Ever tried spear fishing with a polearm?
1. Your right, all the things you can do with a spear you can do with a polearm, but it's not the same the other way around. Also, Polearms have a cutting edge to them but not most spears have a cutting edge to them. They may have a barbed head but they in no way have a "cutting edge". There is a big difference between a Pole arm and a spear.
2. Your right, with spears, it will just be a blunt swing that will most likely not do any damage other than to stagger someone.
3. Spears are not really that fast. They are faster than a pole arm a bit but most weapons are much faster than a spear thrust. They have a reach and poking someone at a long range to the point they can't get to you in the game does not make for good gameplay, it just makes for your character being untouchable.
4. I don't see how a spear fight is more dynamic. Poke, poke, block, poke. Everything you have to do for a spear fight and more must be done in a polearm fight. This is a polearm fight : Swing, swing, block, stab, swing. There is more diversity in the fighting with a polearm and a spear.
5. I'm sure you can fish with a pole arm. Also, polearms can be used for cutting ropes or small trees. Have you ever tried to cut a small tree down with a spear?