We played outside because:
1) We didn't have air conditioning so inside/outside didn't matter
2) We didn't have video games, so inside/outside didn't matter
3) Our parents didn't have 24 Hour news stations on the tube to scare the bejesus out of them and force all the kids inside.
4) in 1970ish if you got into a bit of trouble it was "Boys being boys", in 2000ish we have zero tolerance for anything.