I agree it's not "ideal" distribution, but
1. It's common problem among PoW coins (see charts for different coin).
As much as I hate to say it, ethereum looks like it has the best distribution among all the charts I saw by far. Lots of smaller pieces of pie.
I assume the "unknown" part is just people mining on their on, doing it solo from their basement. so why wouldn't they cancel out??
no actually I was trying to learn about bitcoin and reading over at https://bitcoin.org/en/full-node#minimum-requirements where they say the following:
Bandwidth limits: Some Internet plans will charge an additional amount for any excess upload bandwidth used that isn’t included in the plan. Worse, some providers may terminate your connection without warning because of overuse.
that's a pretty serious warning. surprised they would put it on their site because it seems like it would discourage someone from wanting to run a node.