Lets ask the question, should superheroes always wear capes? I think it depends on two things. The hero, their purpose and costume design. The cape definitely highlights a sort of dynamism. When you open up an actual comic book, you see the pages do not move, so the cape is drawn as cloth fluttering around a character to signify that the superhero is a super, spinning dynamo of action and movement. You have your vigilante types like Batman and Blade who have utility uses for their capes (well Blade wears a trench coat, but you can consider it a cape).
For them, their capes are indispensable tools. The coat/cape has many hidden pockets to store all kinds of items, devices, and weapons that have various need.
CAPE AS A UTILITY
Take The Shadow for example...
His cape is a huge staple within the comic. He would swirl his cloak around him to distract and confuse his enemies. Additionally, The Shadow (and Batman to an extent) cape helps to create a shroud of darkness around them, so they blend into their dark surroundings. Capes provide cover for these characters (and many others), whether they are bullet proof in some way, or visual cover. Lastly, it can also help the hero glide on air if need be (again, refer to Batman)
Capes can save our heroes from flying objects such as shrapnel and can protect them from falls or break their falls when they have no choice. Capes can even help our heroes fly or glide on air (Batman for sure...)
There are instances of where the costume work solely without a cape, as the costume serves its utility purpose without one. Look at Captain Marvel and Captain America.....
The costume is based on military-style uniforms and work as a utility in and of itself. This is key to creating costumes that do not require a cape.
Cape as Fashion/Symbolism
Superman is a good example of this. In his case, as it is a thing of symbolism. The cape creates an 'epic factor.' Superman's frequently depicted as a sort of guardian angel... giving him wings would have been too much. Why not give him a cape instead? I'm sure there is a lot more Kryptonian history involved in the wearing of the cape, but thats another can of worms for another day .....
In the case of Batman its also symbolic...so the cape helps to enhance the Batlook, showing that he is a creature of the night.
Fashion has a lot to do with it as well. Depending on the costume design, a cape is necessary to enhance the look. Would this costume be convincing if it came without a cape? I think not.
Superman doesn't use his cape to manipulate his enemy, or shield him from much of anything. It is just there. To me, his long flowing (probably heavy) red cape always looks cumbersome to wear. If you need reference as to why capes don't always work, look at this scene from The Incredibles:
Personally, I like some of superhero looks without the cape. It looks sleeker, and our heroes look lighter on their feet.
I think in the end it boils down to costume design (not including characters like Iron Man of course because a cape on that suit would look stupid.) Some costumes look fit for a cape, and some, I'm not sure why the cape is there. I guess the bottom line is what purpose it serves and does it make sense in terms of the character. Maybe you guys can educate me more on the wearing of capes. What are your thoughts?!