I would phrase it slightly differently. I don't think it has to be as black or white as you put it, with one group being right and the other wrong. Maualuga can be a 1st round talent but not right for the Pats.
I think Maualuga is a fine player and probably a first round talent in the right system. I've had him going #26 to the Ravens for a while now, and I think that he could be a dynamite player in the Ray Lewis mold in a system which protects him and plays to his strengths. The system that the Pats run now is not such a system, and in fact makes demands which play to some of Maualuga's weaknesses - a schematically complex system requiring discipline to play your area rather than to freelance, and which emphasizes taking on blockers. Those just aren't Maualuga's strengths, regardless of whether you see him as a 2 down or 3 down player. BB could obviously change things to play to Maualuga's strength and protect against his weakness, but that would entail a fairly dramatic change in defensive scheme. I'm not sure that the player warrants that.
I'm happy to accept that SILB is worthy of a 1st round pick, if there is a worthy player in terms of both talent and schematic match. I had pegged Brandon Spikes as such a player. At one time I had hopes that Maualuga would be such a player, but I just don't see it. Obviously, if the Pats see something that I don't I will accept it and hope for the best.
Whatever else, I think it is fairly clear that the average draft expert has less understanding of the intricacies of the Pats' system and draft tendencies than many of the more experiences people on this board. Time and time again some so-called "expert" makes a pick which doesn't fit the Pats style at all. Obviously BB is somewhat unpredictable and has made fools of us all over the years, but I think that we have some idea of what kind of skills are likely to make a good positional fit. Many people look at Maualuga and see a 250# ILB who hits like a ton of bricks and immediately peg him as a 3-4 SILB perfect fit to the Pats. Regardless of whether he actually is or not, it is somewhat more complicated than that.