Planning for predictable but random events is part of your responsibility.

There are many random circumstances that can make a person late. Some are a person's responsibility to plan for. Some aren't.

Consider minor traffic delays. If you're 10 minutes late because of traffic, that's not traffic's fault. That's your fault. A 10 minute traffic delay is not a rare occurrence. You simply shouldn't be operating your schedule with so little margin that a ten minute delay will make you late to something important. If you don't have some margin in your schedule, this is entirely your fault. You built a schedule that only works if absolutely everything goes perfectly right, and then you blamed circumstance when the inevitable happens.

Then there are some delays that it's not reasonable to expect people to plan for. If you're hours late because you had to rush a family member to a hospital, that's not your fault. That's a legitimate emergency. And it's not reasonable for people to build multi-hour buffers into their daily schedule.