No, you're the one who thinks you and your working time are more important than obeying the instructions of the cabin crew. I'm with alanR on this - just turn it off when you're told to - but I don't expect that you will ever agree.

Disobeying instructions just because one thinks they're stupid is also evincing the attitude that one knows better than the crew. Few people have the luxury of genuinely being in that position, and being a frequent passenger doesn't in itself count.