The same reason that people crash their cars. Oftentimes with friends and family inside them.
Sometimes, it's because they did everything they could, within reason, to prevent it.
Sometimes it's because they were reckless, negligent, and should not have been behind the wheel.
We call the first an accident, and the second (if it kills someone) vehicular manslaughter. We litigate to determine which is which.
We also give people leeway in how negligent they want to be. A BAC between 0 and 0.08 is fine... Unless you hit someone - at which point, it will be used against you. A BAC above 0.08 is immediate grounds for arrest, regardless of whether you hurt anyone.
That is what personal responsibility on one end, and enforced social responsibility on the other end looks like. Right now, nobody can be held personally accountable for reckless behaviour with COVID. Either we lift that protection, or we double down on enforcing social responsibility.
