I feel like it should be accepted, but I'm not a native speaker. We should ask some :)
As a native speaker, I agree that "Who here is a Jack of all trades" is also a good sentence. I've reported it, so hopefully they'll accept it soon!
Thanks a lot! I added it as an answer. There have been 7 users suggesting this, that's enough proof that it should be accepted for sure :)
It sounds unnatural to me, but I'm not a native speaker... So we need some comment from one (or better, more)...
"Who is here..." doesn't quite work for this sentence. "Who here is..." is OK, since you're asking if anyone in this location is a Jack of all trades, but the first way does sound a little unnatural. Hope this helps!