BOOLEAN variables with a required command-line argument (e.g. aria-encrypt-tables)

There are some boolean variables/options which are not recognized on a command line or in a cnf file without an argument It does not seem particularly reasonable, and certainly looks inconsistent, because other similar variables work just fine without an argument..

I could suppose that it's a legacy thing, but there are new ones as well, e.g. aria-encrypt-tables. So, innodb-encrypt-tables works without an argument, encrypt-tmp-disk-tables too, but aria-encrypt-tables does not. It's just weird.