Well, the field looked weak even before the start.
However, considering Almeida, Hart and Hindley are all young. And if they win 10 GT's between them in the next years will it still be 'weak field' or the beginning of a new era ?
Now if top 4 had Nibali, Fuglsang, Pozzo, Majka in that order I would be more inclined to conclude that the field is weak.
If that performance remains one of for all of them it's surely compromised GT.
But if what I said about GT wins turns out to be true, in 5 years all the 'weak field' comments will look silly.
As someone said, give it a bit of a hindsight before saying "rider X would just walk with the win in that GT".