The flaw in that argument is the hypothesis that the Patriots and a small handful of others are the only ones able to understand the value of TEs vs WRs. I am not sure that their draft history or FA approach reflects that. In truth, Gronk was available to them because of his injury history and Hernandez was available because his draft interviews came back as "We're not saying he will DEFINITELY kill a guy at some point, but we can't rule it out" for most teams. Since Gronk - and it has only been 5 seasons - it isn't like the Patriots haven't been tying to acquire WRs vs. TEs similar to how other teams have. More teams than not have spent a 2nd or first round pick on a TE in the last 5-6 seasons (I will openly admit....I am not 100 percent certain of this. I know that at least 7 have....but I am not sure whether some guys were 3rd or 2nd rounders for the other teams and I am feeling lazy). And a number of other teams have drafted basketball players late in the draft to try and capture the next Graham or Gates.I'm not necessarily disagreeing with Barnwell's conclusion; I just think his argument is fatally flawed. He's basically saying that all things that are more expensive are more valuable, otherwise they wouldn't be more expensive. He's begging the question.
Let's assume that WR, on the whole as a positional category, are more valuable than the league wide TE group. How much of that is simply due to positional scarcity at TE? I think part of the reason the Pats spend more time seeking out TEs vs WRs is that there simply are more quality WRs to go around. There are only so many human beings on this planet with the unique combination of size and athleticism to be dominant tight ends. One would think that would drive up the price of the top TEs, due to supply and demand. But the demand doesn't seem to really be there. At least, not as high as it is for WRs. A ton of teams are much more likely to seek out the sexier acquisition of a top tier WR instead of a top tier TE.
i don't think that the market inefficiency is all that significant, but I could certainly be wrong.