When we visited Amsterdam as pedestrians, we absolutely hated these bike lane / sidewalk combinations. The problem are the often narrow, obstructed sidewalks forcing you to step into the bike lane. I wouldn't call that "incredibly dangerous" though, after all, we didn't witness any accident, but certainly annoying, especially considering that the most common obstruction is parked bikes.

I guess it takes some getting used to, or maybe the Dutch simply avoid walking and take the bike instead.