"Car takes a left into rider who has nowhere to go" is the leading cause of dead motorcyclists. I, by the way started w/ mini bikes, became a legal street rider in 1985, and have been a motorcycle messenger, road racer, and worked in the industry in the ensuing years.
This is going to sound uncharitable, but any motorcyclist who enters an intersection, or passes any vehicle which has the physical possibility of hitting them or requiring them to make a course correction, without taking initial steps for readiness to avoid that vehicle, isn't doing all they can to be safe.
Successful long-term motorcycling is not a passive activity - EVER. If you're anyplace but an empty road in Montana with infinity view ahead and behind, you have to constantly scan the far and near distance and mirrors. Every car cannot see you, and DOES intend to kill you. Not sometimes - always.
If you're approaching an intersection and there's a vehicle coming toward you - whether or not they're signalling - or even in the lane they'd normally turn from, you have to be aware of how much grip there is in the event you need to use maximum brakes or steering, position yourself off the centerline of your lane for more room and grip, cover the brake if you're not - and you should ALWAYS cover the brake - and be ready to take evasive action.
The lessons learned on track pay huge dividends on the street - familiarity with brake, throttle and steering limits and most of all KEEPING YOUR EYES ALL THE WAY UP! if a threat is recognized 2 seconds sooner it can make the difference.
When I worked in the industry the shop I worked in sold Harley, BMW, Ducati, Yamaha, Buell, Bimota and Triumph. Next to young riders on Yamaha sport bikes, Harleys were the most frequently crashed. BMW riders, who as a demographic spend the most time in the saddle and have the greatest likelihood of having advanced training crash quite infrequently.
It's possible to get caught out. I was about to pass what appeared to be a parked pickup some years ago. It was off the road and pointed slightly away. This is why I couldn't see the left steering input dialed in 'til I was 25' away, and the driver, looking down at his phone, initiated a U-turn nearly directly in front of me. I had the exceptionally good fortune to have taken my old BMW air cooled boxer that day - the right valve cover protecting my leg and mangling a full-size GMC steel front bumper pretty effectively. I was on the ground and sliding 30mph down the oncoming lane instantly. I still feel bad for the poor woman who's car I slid to a stop directly in front of. I was then enveloped by her impressive cloud of tire smoke. I got up to make sure she was ok, and she was mute, ashen white, and death gripping the steering wheel. She wouldn't respond to verbal commands for a few minutes.
The sad part is that Harley rider will brush it off as a near miss, and not anything he could have taken an active role in preventing.