The chief pilot at the last company I worked for used to do this. I thought he was retarded. He used to also remain 200 ft high to remain out of the tops of cloud, instead of requesting a higher altitude. The funny part was, he thought he was being sneaky by resetting his altimeter so that is still read the correct altitude. Unfortunatly, his pea brain didn' t know that encoding altimeters send pressure altitude to the ATC radars, so it doesn't matter what setting you have in the altimeter.