I'm all for improving the #3 WR position. That doesn't mean that Witten isn't still very effective even when he is targeted a lot.
Among the tight ends:
Rank PLAYER TEAM REC TAR %
1 Dustin Keller, TE NYJ 28 36 77.78%
2 Fred Davis, TE WSH 24 31 77.42%
3 Brandon Myers, TE OAK 79 105 75.24%
4 Tony Gonzalez, TE ATL 93 124 75.00%
5 Garrett Graham, TE HOU 28 38 73.68%
6 Jason Witten, TE DAL 110 150 73.33%
7 Zach Miller, TE SEA 38 53 71.70%
8 Joel Dreessen, TE DEN 41 58 70.69%
9 Heath Miller, TE PIT 71 101 70.30%
10 Rob Gronkowski, TE NE 55 79 69.62%
Of the top 50 players that were targeted the most:
Rank PLAYER TEAM REC TAR %
1 Randall Cobb, WR GB 80 104 76.92%
2 Brandon Myers, TE OAK 79 105 75.24%
3 Tony Gonzalez, TE ATL 93 124 75.00%
4 Jason Witten, TE DAL 110 150 73.33%
5 Darren Sproles, RB NO 75 104 72.12%
6 Heath Miller, TE PIT 71 101 70.30%
7 Eric Decker, WR DEN 85 123 69.11%
8 Andre Johnson, WR HOU 112 164 68.29%
9 Wes Welker, WR NE 118 174 67.82%
10 Michael Crabtree, WR SF 85 127 66.93%
Witten is turning targets into receptions. You can and should improve the #3 and #4 WR roles and also the #2 TE position(either by adding someone or Hanna getting better), but targeting Witten is in itself not that big of a problem. Plus it isn't as if it is taking away targets from Dez(14th) or Miles(30th).