So I am going to make this real simple. I had four major issues with the traditional roasters I have used which I will discuss in length.
Difficult to Turn
Not Awesome Enough
I realize a short roasting stick provides lightness, maneuverability (important for not smacking your mallow or dog into the ashes) and would be just fine if you had a small fire... That being said, I usually roast on family camping trips, in the back yard, essentially I am always with people. Most of the time it's done in the evening, and it's cool. Cool temperatures often means cold people. Cold people means the fire is kept blazing hot and large. Short roasting stick + large hot fire + hunger = burnt arm hair and or possibly singed eyebrows (although I haven't done that yet). Also burnt arms is definitely not a proposition my four year old is willing to bare. So while a short roaster is fine for small fires, a small fire seems to remain a quaint idea that always loses the "it's cold, put more wood on the fire!" battle.
I'm not to sure why most commercial roasters seems to be constructed in such a way that you would think rubber would have more rigidity than the steel wire setup they often utilize, but I am assuming it's much like the potato peeler example.
Oxo the brand of kitchen wares many years ago released a redesign of the simple traditional potato peeler, which traditional peeler now is not very common anymore. Perhaps you remember the traditional one. I know my hands do. It was constructed from a steel band for the handle, and was really obnoxious to grip. If you have watched the documentary Objectified
(a link to the trailer) it talks about the designers inspiration behind the redesign. His wife had arthritis and complained about the difficulty of gripping the potato peeler. And so he had the thought to enlarge the handle and rubberize it. It was a raging success of a product.
My point being that some poor designs keep getting used not because someone thinks that it's a good idea, but because no one has taken the time to think of something better. Much like the potato peeler, the roaster remains likely unchanged because it serves it's purpose, and most people get along fine with it.
Difficult to turn...
Burned campfire hot dogs and marshmallows are a staple of our family campouts. Mostly because of impatience to roast the food. You stick it close to the coals because you're hungry, and then a few seconds later when you check on it, you have a lovely charred black skin on your food. Mmmmmm, delicious. Of course you could solve this by slowly rotating your roaster which would allow it to remain close to the coals, not burn, and be cooked through quickly. However, most roasters I use have rectangularly shaped handles. I've even use some rounded handles. And while it's possible to rotate both in your hand, it's difficult to remain concentric in your rotation, while making it difficult to avoid ash, or flames, and making the prospect of roasting food that much more obnoxious.
Not awesome enough...
Roasting sticks are boring, I think a pointy wooden tree branch is more interesting than most roasting sticks I have seen. If I am going to put down some money for a dedicated roasting utensil, I want it to have some awesome-looking features. It makes me feel good about the money I spend when the product is not just functional but aesthetically pleasing. And a roasting stick for me represents frivolity and fun. Of course I can microwave my marshmallows for smores (kind of gross though), and I could roast my hot dogs in the oven. But that isn't nearly as fun as having a camp fire, and spending some time outside with my beautiful wife, and ridiculously silly kid in the great outdoors of our backyard. Therefore there must be more awesomeness and attractiveness added to the traditional weenie roaster setup.
The theoretical solution (at least for me)...
The perfect roaster would be stiff, collapsible, easily rotated, and long enough to have a warm fire, but not so long that you have to let go of the handle to reach the tip.