> Why would you want to turn bluetooth off but not really turn it off?

A typical case I used to see is "let me switch off bluetooth so that my car doesn't keep connecting while I connect it to your phone" combined with "hey, how come my watch isn't connected to my phone?"

Now it works as the user expected.

This isn't how you or I might expect it to work but I suspect it satisfies most users' mental models.

This isn't intended to praise or condemn the behaviour, I'm simply responding to your question.