If we're going by that metric, apes / baboons won't be able to hold anything either because their "hands" aren't actually as good at manipulating / holding stuff as human hands are. And yet a chimpanzee can use a tool to pull ants out of an anthill (for example).
I've seen raptors (falcons, eagles, etc) grasp other birds, lizards, small mammals, and fish in their talons; and they can hold other things too (seriously, check out some falconry sites; it's pretty interesting how they are trained and what they do)...the problem is that nobody has actually seen a dinosaur do similar things because all we have to go on is the morphology of the bones and other things like feather imprints, trackways, etc.
Everyone agrees that the forelimbs were used to grasp; the question is how much they could.
It would cost one natural attack (and using a buff to a stat that doesn't necessarily help in combat and has no mechanical benefit at all except for something like this) to set it up but it just seems like a cool thing to do.
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Of course, I'm enough of a naturalist to have some issues with other rules / justifications like the parrot...if one wild-shapes into a parrot one can control all one's muscles in a complicated manner EXCEPT the syrinx (the larynx equivalent in birds that lets parrots, ravens, mynahs, etc produce speech sounds)...but that's another issue entirely...
