The problem is that "people can make that decision for themselves" only works if they themselves pay the price for their actions. If you're in the age range that is likely to get an asymptomatic or mild development, the price of you getting infected and walking around infecting others are paid for mostly by others.

"Let everyone decide for themselves" rewards the selfish and makes people that restrain themselves jealous of the selfish people. If that's the kind of society you want to live in, well, that's your choice. But I think a lot of people don't.