Tip: You can disable cores for CPU-Z/geekebench if needed... But true it won't be sufficient to be competitive versus the Skylake CPUs due to way lower achievable clocks.
You are right looking at the bechmarks and co that it is easier for mainstream 2-4 core cpus, that sport already higher stock clocks and OC way higher on H20 than your 6950X...
Now look it from the other competitors' point of view... The way the benchmarks are selected it allows you to enter and maybe get a chance to be present at the bootcamp with an affordable processor like an I3-6300.
That is what it is all about, not about who has got the most expensive hardware and gets an easy ride to compete in Berlin. If HWBOT only adresses the ones with a 6950X we would only have 10 entries. It is far more viable option to make all competitions accessible to a wide public.
For all competitions you need to make a proper selection of the hardware you will best use and the 6950X is indeed limited in many aspects...