Copenhagen tends strongly towards segregated lanes: you have to be extremely familiar with the city layout to be able to pre-empt where to enter & exit, and local cyclists come across quite aggressive if you're not constantly perfectly aware of where you're supposed to be going (and going fast enough for them). The lanes are claustrophic and hurried.
Turning at junctions works quite well (cyclists cross with traffic and loop backwards to wait to turn, rather than crossing lanes), but only with very large junctions; this doesn't scale downwards.
In the Netherlands on the other hand, road-sharing is very much the norm. The sheer number of cyclists means bad behaviour just does't seem to be an option for motorists: safety in numbers.
I think this is the real answer. I've seen "fundamentalist" behaviour from fellow cyclists, and it bothers me, but I think it's reactionary when the relationship with other road-users is strained. With growing numbers of cyclists, and shared road-space, I think this wanes. This has been my experience in Dublin anyway: nowhere near the numbers of Amsterdam, etc, but still, the numbers have significantly increased in recent years and the relationship has noticably improved (anecdotally).