Being a police officer isn't a dangerous job, it isn't even in the top 10 of most dangerous jobs in the US. No one thanks the 7-11 clerk for the danger they put themselves into so you can buy a Slurpee at 2AM in the morning. No one thanks the crab fisherman who risk their lives so you can enjoy "all you can eat" snow crab legs at Red Lobster.
There's lots of extremely brutal jobs that are thankless. People who pick your food. Visit central California during summer where people are picking produce in 100+ degree weather for 10 hours day. It's hard back breaking work.
Being a police officer is a well paid job with a pension where most of your day is filling out paperwork.