Mechanicals are to blame imo, carbon shafts too as they are light.  Carbons penetrate foam better than aluminum, but I think that is due to the smaller diameter.  Not the same on flesh when there is a big broadhead leading the way.   
I used to be a freak about penetration.  My last "penetration" bow was a Martin Fury, shot at around 76 lbs, shooting 2419 with the original Phantom 4 blade.  The arrow weighed close to 700 grains, and was chronographed at 265fps.  It sounded like a boat paddle hitting a bucket when I'd hit a deer with it.  When I set it up, the guys at the bow shop asked just how far in the dirt I wanted my arrow to stick after going through a deer!   In the field, it was impressive. 
Since those days, I've switched to mechanicals, lighter poundage, and carbon shafts.  I came to the realization we are shooting deer with skin about as thick as a Tshirt.  They aren't hard to kill if you shoot them in the ribs.  Even with today's set-ups not blowing through deer as the old ones did, I think for the greater good of the sport and increased participation, mechs and carbons have made it easier for the masses to KILL deer.   Once upon a time, it took a little work to get those shovels to fly straight.  With mechs, any nimrod can hunt and shoot as accurately as they do with field points.