Source - Foot surgeon in my family.
1. If something is heavy enough to crush the steel toe to the point of amputating your toes, your toes are going to be amputated anyway.
2. They can save you from smaller injuries that could put you out of work or in great deals of daily pain
He says the myth that it's better to have crushed toes vs amputated toes from a steel toe boot is 100% false. First, he sees very few actual crushed steel toe footwear. Maybe a couple a year at most. He has never, ever, seen an injury from crushed steel toe that he felt the toes could have been otherwise saved had the user not worn steel toes. He does, however, see a TON of injuries that COULD have been 100% prevented by steel toe footwear. This man sees thousands of foot injuries a year...mostly industrial injuries.
Absolutely zero reason to not wear steel toed footwear. None.