The days of being able to afford to have a battering ram in your backline are coming to an end if they are not already long gone. While yes we need his hardness, and we have just come off a final where we were extremely soft, you really need your half back flankers to be able to kick and kick precisely-AND do the hard things. You're never, ever going to get the kicking from Morris so you are conceding a huge kicking weakness in an important area as long as he is in the side.
I think he is exposed in zone defences too, he is strictly a one on one player, who seems to have lost a yard.
Players of Morris' type are usually lucky to last 100 games so we should be planning for life without him anyhow.