- Poor IOL personnel, made much worse by the Mankins trade
- A pair of OTs who struggle against elite speed, and one OT (Solder) who struggles against top strength as well
- Stupid idea to rotate a lot on the line when you just got rid of your best OL a week ago
- Facing the Dolphins in the heat of the day
With that, why would anyone say this was surprising?
I would completely agree with your post that the poor play of the OL in this game (particularly in the second half) is hardly surprising. The reasons (I won't call them "facts") I would list are different (except for 4.), basically they have to do with heat/conditioning, and the continuity that so important on the OL and the overall Offense:
HEAT/CONDITIONING
1. Sweltering heat that the Patriots simply could not handle in the second half
2. New rules that limit contact in Training Camp, presumably affecting conditioning
OL / OFFENSE CONTINUITY
3. Loss of Scar (I'm tempted to repeat this bullet five times)
4. Loss of Mankins
5. Fewer padded contact reps in camp
6. Players with extremely limited reps at a new position (Cannon, Devey)
7. Key players (Gronk, Dobson) shaking off the rust
When those factors are combined with the strong Miami DL and the way that Miami has been completely discounted in the off season (did you see the fire in the eyes of the DL in the second half?), to me, as you said, it is completely unsurprising that the OL laid an egg, particularly in the second half.
Now, if they play bad (I won't say "as bad", because that would be almost impossible) in Minnesota, then I'm really going to start panicking.