One of the subtle things I took from the Reggie Wayne experiment was how difficult it is to master the Pats offense combined with the fact that playing for the Pats (at any position) is HARD, harder than for most teams. By all accounts, Wayne was a good guy, a smart guy, and a hard working guy; yet he didn't find short experience with the Pats to be easy OR fun. So when we look at people and want to fit them in to the Patriots' puzzle, it's best to remember that this experience isn't for everyone and even if it is, the learning curve is steep.
BB has had weeks to plan for this season knowing Tyms and Gibson were gone, and sizing up not only his receiving corps and others. He likely knew over a month ago that LaFell was going to be on the PUP and what we see is likely what we get.
I think this entire rumor that the Pats are looking for a big receiver is way overblown. The odds of someone being available us at this point, coming in and being a significant contributor THIS season is slim and none. BB is always looking at other team's rosters for players, but I doubt very much he's looking for a WR in particular. RB would be more likely.