Antisocial people with a car are just as dangerous, in fact even moreso. Being killed on public transit is so rare that you had to bring up an example from over a year ago; hundreds of people are injured/killed with a car every day.
Yes look at the statistics (and the existence of "road rage" while there is no "public transit rage"); they show that public transit is far safer than individual cars, and people that aren't afraid to give it a try see that it really is that way. I have never been threatened with a knife by a public transit rider. I have never been threatened at all by a public transit rider. I have never seen anyone else be threatened by a public transit rider. When someone seems like they're going to do something, there is often a way to silently report it, and the cops come quickly and take the person off if appropriate.
On the other hand, being threatened by drivers is a near daily occurrence. They verbally threaten to run others over, to punch others, to shoot others. They inch their car closer to others, rev the engine, etc. as a threat to crash into others/run others over. The cops do nothing about it even if you have pictures and video. I had a someone run into me on purpose once. I got pictures of him, his car, and his license plate. The cops did nothing.
You have a false sense of safety when you're in your car. It's just marketing. No one wants his wife, daughter, mother, etc to be Iryna; so instead they risk the much more likely risk of their wife, daughter, mother etc. being one of the people whos name we won't even remember because there's so many of them.