Per-target numbers are junk. The target is not the proper unit of opportunity for a WR, the route run is. Also: YPA has a known bias towards deep passes, and that bias also applies to per-target stats, but exacerbated since it's a smaller sample size.
Don't believe me? Here's every season by a WR with 50+ targets and 11+ yards per target since 1992 (as far back as PFR has target data):
2015 Sammy Watkins
2015 Torry Holt
2014 Desean Jackson
2014 Kenny Stills
2013 Kenny Stills
2011 Victor Cruz
2011 Malcom Floyd
2011 James Jones
2011 Jordy Nelson
2010 Desean Jackson
2010 Mike Wallace
2009 Robert Meachem
2008 Devery Henderson
2008 Steve Smith
2007 Anthony Gonzalez
2007 Santonio Holmes
2006 Devery Henderson
2006 Joe Horn
2005 Santana Moss
2004 Plaxico Burress
2004 Lee Evans
2002 Dennis Northcutt
2000 Torry Holt
2000 Randy Moss
1999 Tim Dwight
1999 Az-Zahir Hakim
1995 Qadry Ismail
1993 John Taylor
That's... not a very good list of WRs. There are a couple of great ones on it, though usually only once, and usually early in their careers when they were still a complementary piece rather than the main guy, (or, in Joe Horn's case, late in his career when he was just a complementary piece instead of the main guy). But about 90% of those seasons have something very obvious in common- the player was just a one-note deep threat.
Now, Sammy's total targets is towards the top of that pack (13th in total targets, 7th in targets per game, one of 12 players with over 6 targets per game). I'm not saying he's Robert Meachem. I'm saying receivers average more yards per target on deep routes than they do on shallow routes, so Sammy Watkins' YPT averages aren't comparable to Antonio Brown's or Julio Jones' because Sammy doesn't run any shallow routes and those guys do. Watkins huge per-target stats have much more to do with his role than with his talent.
If Buffalo kept Sammy's 6.75 targets per game as a pure deep threat, and they added another 4 targets per game on short-to-intermediate routes, Sammy Watkins' per-target stats would drop by a pretty substantial amount. But Sammy would wind up with more targets, more catches, more yards, and be a bigger part of the offense. It would be an unambiguously good thing for him. And honestly, Buffalo should do that- we saw him roast Revis, (who isn't REVIS anymore, but who is still a quality cornerback), on those quick out routes. Watkins was a YAC monster in college and would be a beast on screens in the NFL.
I think Watkins is a star. I've already gone on record that he's probably going to be my "Litmus Test WR" in 2016- the guy I bring up to see who is actually watching the games and who is just reading the press clippings. (Past "Litmus Test WRs" include Jordy, Antonio, and DeAndre.) But I don't think his per-target stats are the way to demonstrate it. All they show is that Buffalo has stupidly been using their super-expensive, super-talented weapon as a one-trick deep threat.
