You may as well ask why perfectly healthy people park in handicapped spots. Or park in the middle of two spots. Or a few dozen other questions that only have one answer. Some people care about nothing except themselves.
A related question about the safety of our children. Why are school buses exempt from mandatory seat belt laws (except for the driver)? This infuriates me because the only reason they aren't required on school buses is money.
When my kids were in school, I refused to wear a seat belt because kids on school buses don't have seat belts. Over a 3-year period, I was pulled over twice for violating the state's mandatory seat belt law.
The first time, when I told the officer that I would start wearing my belt when kids on school buses could do the same, he looked at me for a very long time, then handed me my license, tipped his hat and said, "Drive safely, sir."
The second time I was given a citation for which I appeared in court, again explaining the reason. The judge nodded his head, found me guilty and fined me $1. Last I heard, the normal fine is $325.
My wife finally convinced me to stop tilting at windmills, but I still believe it's criminal that untold thousands of children are put at risk every day because it would cost too much money to put seat belts on all the buses. Some things are more important than saving money.