Yeah, they didn't used to be so strict about it. I have never had to turn it OFF. I always have just had it in airplane mode in my pocket, or at least not using it. But on the last few flights I have taken, the announcement has been that it has to be OFF, and that airplane mode was NOT OKAY.
Not that I always pay careful attention to the safety announcements, but I guess some people can't wait to kill one more pig or zombie or whatever.