Aye. It is.
Plus can you imagine trying to enjoy your flight if lots of people took him up on his suggestion? 'Brother, I notice you didn't raise your hand when the pilot asked who was a Christian- would you like to hear my testimony?' Or, 'The Holy Koran says...'
It's not what I want on a flight.
Nobody on that flight paid for a Sunday school class. I don't think it's anyone's business to be asking me about my personal religious beliefs. Especially someone who should be focusing on flying the damn plane.