Isn't it mostly the fact haki is confusing as hell that makes people hate it? I know that's the reason I hate it.
It’s a mix of both
I’d argue people that find it confusing are just straight up correct though
Oda hardly explains shit and his visual indicators are super inconsistent. If Togashi is critiqued for too much text and overexplaining everything Oda is almost the complete opposite regarding haki
Once he explains whatever form of haki is relevant at the moment once or twice he pretty much never brings it up or references it again (maybe every few hundred chapters?)
How do we know someone is using future sight? We don’t
How do we know someone is using advanced conqueror’s? Lightning!
Except lightning is also used as flair for armament as well
People are still debating whether Koby’s Honesty Impact is an ACoC technique or not. It was also heavily debated whether Garp had CoC at all until the vivre cards came out
It’s just a jumbled mess. I’m a massive OP fan but I’m not blind enough to say it’s a good power system