Mark, the larger problem is that most LEED consultants have never DESIGNED anything, so they should restrain themselves from doing anything more than suggesting LEED product goals/requirements and products they know have been adopted in previous projects. LEED consultants should NEVER write specifications; that's the job of the design professionals.
All good points about specs, but "LEED consultants" is apparently a pretty broad term. We are professional LEED consultants, not designers who profess to do LEED also, and we find most of these well taken criticisms to be perpetuated by Master Spec and designers who don't have practical experience with applying LEED in the field.
As LEED consultants, we spend a lot of time editing this kind of stuff out and preparing bidder's requirements that speak directly to contractor issues. Designers don't always have a practical, constructability-oriented mindset whether working on LEED projects or not.
This is an important issue of education and awareness. And the emphasis is significant. I have seen several design teams go through enormous effort to figure out how to "pin" the contractor on MR4/5 compliance through the specification. That's likely 2pts among the 40 to 60 they are pursuing, when 2/3 of what is needed will be design points that they are nowhere near conversant enough with or accountable enough for.
Whether LEED consultant or designer, the professional involved should have practical field experience with design and construction to be an effective sustainable design practitioner. It's unfortunate to cloud such an important issue with generalizations about either.