Its a question of compromise, as you say in your avatar "you cannnot negotiate with gravity"- I like that.
A g/f pole can be made stiffer by making the g/f thicker, but the you add weight, or by using c/f then you lose robustness. The 25 and 30fters may not be released because c/f modular may be the better way to go. Its also down to cost, for domestics we think the Ninja tapered telescopic 21fter@£85 delivered, is fast, light and very competitively priced and will take more knocks and can bang it against walls and roofs - all day, than c/f