There were several clubs with first round picks who had him only a small few places down their power rankings behind those they took, then those clubs with second round picks didn't rate Murphy as highly.
In that regard Collingwood got lucky with Western Bulldogs, Greater Western Sydney, Sydney and maybe one other club having some interest in the first round.
At the end of the day, if a player isn't number one on your draft board/preferences list at the pick, they will keep sliding until they're top of someones list.
Sorry, I should re-word my original question. Why do you think Murphy wasn’t rated too highly by most clubs? Based on the limited highlights of him available, he looked to me to be a very attractive utility with good attack on the footy, excellent hands and a decent kick.