It's been on my todo-list over neat ideas for a while. I just assumed someone would've beaten me to it by now :)
I suspect it might have to do with resources - dedicating multiple cores to benchmarking isn't going to be easy to do for free. Might be feasible for low cost, though.
Why haven't you? That's probably why no one else has :-)
Instead be surprised that someone has continued to push the benchmarks game along, and that people have continued to contribute programs gratis.