Highfly3d: yup, CPLR wins with a T-can and they appear on airplanes faster than dandelions in my lawn :-0
CPLR wins with radically swept wings and... well, you know the rest.
The pattern market is VERY small (globally, not the just in the USA); so sellers want to provide designs that they feel will sell. The Japanese designers tend to make continued improvements to their existing designs which have evolved over several to many years. Even they are jumping on the swept horizontal surface bandwagon.
There are a few innovators who have been willing to follow their own design philosophy; Alex Voicu produced the Vortex design which has now been kitted in the USA, for example.
Anybody can try their hand at designing their own model, but the effort would still be substantial as the weight limit poses significant restrictions as does the current F3A schedules. Of course designing your own ship for the lower classes would be potentially easier as schedules are much less 'knife edge' intensive. I'll add that there also the expense to be considered as a 2 meter design will require a lot of balsa (or producing a plug and a light weight fuselage) and contest balsa is pretty pricey. Mostly, I think guys are quite happy to spend the extra money to get an ARF and avoid the effort involved in building.

CXXXV:
I always loved the Brushfire (and still have a kit). The big 'goal' in current pattern flying is constant speed and that seems to have been translated to mean slow speed; so full throttle is mostly only used in vertical flight (and even then only if needed). The plus side of slow flight is that you have more time to fly through the maneuver which is especially beneficial to current pattern pilots as it seems the majority are well over age 50. Personally, I still fly glow and 2-strokes to boot. I fly slower than the old 'Brushfire' days, but faster then what is considered acceptable in current thinking (until it gets windy). Back to the point; to fly slowly with control authority, more throw is needed which leads to the twitchy feel when flown at greater speed. Just my opinion, since I have not flown the model you flew. What do you plan to compete with next year?
PS - your electric Brushfire looks great! Back in the 'good old days' pilots would have been thrilled to fly an 8 pound Brushfire.