What the A's saw was a elite athlete. His speed and athleticism are completely obvious if you watch him take 20 snaps as a QB.
If the A's saw enough in his swing to project him has a 20ish HR guy with the ability to steal 50+ bases and cover a lot of ground in the OF as a possible CF then you might have a 1st rounder. The obvious comp is McCutcheon who without the 3 years of his prime was a .275 20 HR 20SB guy. Also a 5 time all-star. Not bad.
I don't know anything about all the guys in the stat rundown above - but I would be willing to wager that none are the physical specimen Murry is. You can't teach size or speed.
I understand the argument that he might have been a reach in top 10 - but if he can hit - a big IF, then there is little doubt he would have been worth it if he came anywhere near what McCutcheon was.
My estimate is that there was a 1 in 10 shot of that happening. 40% - 60% shot he'd be a journeyman 4th OF and 1 in 3 on bust. If you use the draft to swing for the fences then it makes sense. If you are at #9 and want to be sure you have a 80% shot of a competent MLB player that has a 10+ year career - then Murray probably isn't the move.
But remember guys still fail. Try these names out Cuddyer, Zito, Baez, Whitson, Rowell, Crow and Pelfrey. All guys drafted 9th in the last 20 years. There are others but the point is that the MLB draft is he least knowable of all drafts and some teams will luck into good players or lose on prospects widely held in high regard.