Those bros in their 50's are part of the population that basically grew up without the benefit of suncreens of any kind. If you went to the beach in your 20's it was assumed that you were going to have to get tanned gradually just to be able to withstand a day in the sun. No such thing as SPF 50 in 1970!
The girls in SE Asia are covering up for the same vain reasons that westerners tanned, their just doing it for the opposite skin tone, not because of a fear of skin cancer. Still, they luckily picked the right side of that vanity.