But what is the "shrewd negotiation" that he's failing to show? He offered the most Portland could to Turk. Turk took a bit more to go to a city he preferred. He's now (depending on the veracity of the report) offered a lot to Millsap and in a potentially creative way. Ultimately, I don't think free agency boils down to shrewdness in negotiation. It comes down to identifying the right guys to go after (which is talent evaluation, something you seem to have faith in with him) and then hoping they pick you. Basketball cuts out the "bidding" step, by and large, by standardizing contracts. Outside of certain free agents, most seem to boil down to offering everything you can...either all your cap space up to the max or the MLE.
It would seem to me that Pritchard showed plenty of shrewd negotiation in the Aldridge deal, the double-deal that acquired Roy, the deal for Bayless or the maneuver to steal Batum away from the Spurs.
I'm not saying that Pritchard is a perfect GM or any such thing. But judging him based on free agent activity seems like a bad idea, because significant free agent movement isn't tremendously common and when it does happen, there doesn't seem to be a lot of art to it. Offer what you can, see what they choose.