Do you ever find yourself wishing a WR would put a few points into blocking and STR? How many huge runs have you missed out on because the WR couldn't hold a block for 1/2 second?
If the sim were more realistic, the WRs would at least have higher strength. Look at the guns on guys like Steve Smith (Carolina), Plax (no pun intended), Hines Ward, etc, and you can tell that they use strength to get seperation from coverage, pull in contested passes, etc. The side benefit from the sim requiring more strength to receive would be, of course, WRs better equipped to block.
Most of the teams I'm involved with that have WR's with 30+ strength notice them blocking very well on pitches. Blocking isn't nearly as useful at strength, which serves multiple purposes, and yeah it's a good idea to at least train it up for WRs.