1. Kamas can be dual-wielded, while fists cannot be. Fists use gloves for their extra damage and for DR penetration (although the monk can penetrate some DR even without gloves). Gloves are not as flexible as weapons with their item properties, but do cost less. Using gloves however, means you are not using bracers for your normal armor bonus and protection (so kama using can make use of another item).
2. Gloves have an AB bonus. This is what penetrates damage reduction. Monks also get some free feats as they progress in levels, but the feats do not stack with the AB bonus on gloves, making the feats redundant. In SoU and HotU gloves are almost reliably given a damage bonus in an element, rather than physical damage. Also gloves in these modules are often available at AB levels higher than weapons found at the same point in the module. Servers may follow this "balancing," especially if item level restriction is switched on, as item properties on gloves cost less than on weapons.
3. Dexterity doesn't do that much for the class. Technically monks have dexterity as their primarily ability, thus if a character whose first character level was in monk decided to polymorph into another form, then any standard spells granted to that form would use the dexterity modifier for DC, however, most of these standard spells are of little significance by the time you can get the polymorph form to cast them. Dexterity does help other classes, like rogue and shadowdancer which can be used to take epic dodge and self concealment, but the monk cannot qualify for these on his own.
4. Only flurry of blows is the kama supported feat, though kamas do benefit from the monk unarmed progression. The others (circle kick, stunning fist, and quivering palm) all require the monk to be unarmed.
5. The monk is amazing in damage. Even with one kama, his flurry of blow progression rivals the battleaxe due to the sheer number of attacks he can make per round. Called shot is an amazing feat for the monk, because when he targets the arm, his large number of attacks work to his benefit at decreasing the AB of his attackers.
6. You cannot dual-wield fists. However, the monk AB progression alone is better than the AB progression for dual-wielding by itself. Kamas, of course, get the best of both worlds.
7. Wisdom gives AC and determines the DC for stunning fist. It is also used for druids/shifters in qualifying for advanced polymorphs. These polymorphs will often use creature weapons, which is to the monks benefit. When using creature weapons, you can penetrate DR up to the level of your own DR. Thus a monk will often be penetrating +5 or higher DR, get extra attacks, a high AC, a high stunning fist DC, and have the potential for strength, dexterity or constitution (sometimes all three) to be largely increased.